SkatterBencher #52: Intel Core i9-13900K P-core Overclocked to 6500MHz

We overclock the Intel Core i9-13900K P-core up to 6500 MHz with the ASUS ROG Maximus Z790 Apex motherboard and EK-Quantum Delta² TEC.

This is a bit of a different overclocking guide than my previous Raptor Lake content. Since I already overclocked the Core i9-13900K in SkatterBencher #49, I want to focus exclusively on the P-cores in this post. Furthermore, I will leverage Intel Cryo Cooling Technology to achieve frequencies that typically cannot be reached with regular cooling.

Rather than approaching this guide from the beginner’s perspective, I will assume anyone reading this uide already has the basic knowledge of Intel CPU overclocking and focus on the tuning approach for this specific system.

Either way, I hope you will still enjoy the blog post.

Intel Core i9-13900K P-core: Introduction

The Intel Core i9-13900K is part of the 13th generation Intel Core processor lineup.

Intel Raptor Lake builds on top of the performance hybrid architecture introduced with 12th gen Alder Lake. So, it also features Performance P-Cores and Efficient E-cores. Like Alder Lake, it is built on the Intel 7 process technology, formerly known as 10nm Enhanced SuperFin (ESF). While it may sound like Raptor Like is not much different from its predecessor, the spec sheet reads quite impressive.

raptor lake performance hybrid

The Raptor Cove P-cores in the Raptor Lake CPUs are an evolution of the Golden Cove P-cores in Alder Lake. The improvements mainly consist of higher frequencies, increased L2 cache, and a new dynamic prefetch algorithm. Compared to its Core i9-12900K predecessor, launched one year ago, the 13900K P-core has a 600 MHz higher maximum turbo boost frequency and eight additional threads while costing $60 less.

raptor cove 13900k p-core

In this blog post, we will cover five different overclocking strategies:

  • First, we unleash the Turbo Boost 2.0 limits and enable XMP 3.0
  • Second, we overclock using ASUS AI Overclocking technology and XMP Tweaked
  • Third, we get into the manual tuning of Raptor Lake P-cores
  • Fourth, finetune our manual overclock using Intel’s OCTVB technology
  • Lastly, we’ll explore the limits of the P-cores using the Cryo Cooling Unregulated mode
13900k p-core overclocking strategies

However, before we jump into overclocking, let us quickly review the hardware and benchmarks used in this post.

Intel Core i9-13900K P-core: Platform Overview

The system we’re overclocking today consists of the following hardware.

ItemSKUPrice (USD)
CPUIntel Core i9-13900K600
MotherboardASUS ROG Maximus Z790 Apex700
CPU CoolingEK-Quantum Delta² TEC
EK-Quantum Power Kit Velocity² 360
EK-Quantum Surface P480M
EK-Furious Meltemi 120 (x4)
540
686
150
90
Fan ControllerElmorLabs Easy Fan Controller
ElmorLabs EVC2SX
20
32
MemoryG.SKILL Trident Z DDR5-7200 CL34 32GB310
Power SupplyEnermax MAXREVO 1500W370
Graphics CardASUS ROG Strix RTX 2080 TI880
StorageAORUS RGB 512 GB M.2-2280 NVME120
ChassisOpen Benchtable V2200

ElmorLabs EFC & EVC2

I explained how I use ElmorLabs products in SkatterBencher #34. By connecting the EFC to the EVC2 device, I monitor the ambient temperature (EFC), water temperature (EFC), and fan duty cycle (EFC). I include the measurements in my Prime95 stability test results.

I also use the ElmorLabs EFC to map the radiator fan curve to the water temperature. Without going into too many details: I have attached an external temperature sensor from the water in the loop to the EFC. Then, I use the low/high setting to map the fan curve from 25 to 40 degrees water temperature. I use this configuration for all overclocking strategies.

The main takeaway from this configuration is that it gives us a good indicator of whether the cooling solution is saturated. Suppose the CPU is at TjMax, and the water temperature exceeds 40 degrees Celsius. In that case, it means the fans are at maximum speed, and thus the cooling solution is saturated. Improving the cooling solution by adding radiators or changing to more powerful fans would be the right action.

Suppose the CPU is at TjMax and the water temperature is below 40 degrees Celsius. In that case, it means the cooling solution is not saturated. Therefore, to improve the CPU temperature, you may enhance the thermal transfer of the CPU heat into the loop by changing the thermal paste, delidding, or changing the water block.

fan curve cooling saturation

EK-Quantum Delta² TEC

The EK-Quantum Delta² TEC is EK’s fourth-generation TEC water block. It incorporates the improved Peltier element from the Delta TEC EVO and the improved controller electronics from the Delta TEC EVO E2. Additionally, it’s moved from the special edition QuantumX portfolio to the premium Quantum line portfolio. Accompanying the portfolio transition is also a total overhaul of the product design.

ek delta tec generation

The improved 200W Peltier element extends the maximum CPU Package Power capability to 260W with the Core i9-13900K P-core and E-core enabled. That’s quite impressive!

ek-quantum delta2 tec 13900k prime95

The Delta TEC series emerged when Intel introduced the Cryo Cooling Technology in 2020. Intel Cryo Cooling Technology is an intelligent sub-ambient cooling product that offers a new and improved overclocking experience on a desktop. I extensively covered this technology in SkatterBencher #19, so I won’t go into detail in this article. But for those who don’t know this technology yet, let me quickly get you up to speed.

The Cryo Cooling technology is built around the thermoelectric or Peltier effect. Simply put, the thermoelectric effect is the conversion of differences in temperature to an electric voltage and vice versa.

The main advantage of Peltier cooling for PC enthusiasts is that it allows you to get sub-ambient temperatures. That translates into increased overclocking potential. However, there are also some downsides to Peltier cooling.

  1. Condensation. A Peltier cooler can produce a temperature difference of up to 70c between the hot and cold sides. So, the cold side will operate at a lower temperature than the ambient. This will create condensation … which doesn’t mix well with electronics.
  2. Efficiency. Peltier cooling consumes disproportionally high amounts of electrical energy for dissipating heat.
  3. Cooling. To maximize the benefit of the Peltier, you need to cool the hot side sufficiently. High-performance Peltier units like the one included with EK’s Delta TEC are rated up to 200W.

The Intel Cryo Cooling Technology offers some unique features that make it stand out in the market as usable in daily systems.

  1. There’s a software solution to control the Peltier temperature. In Cryo mode, the TEC cooling is only switched on when required and is switched off when not needed. This reduces the overall power consumed as the TEC is not always running at maximum capacity.
  2. The controller also measures the humidity in the room. Based on this input, the controller can adjust the TEC temperature to always be above the dew point. This helps to avoid any condensation issues.
  3. It maximizes the impact of the Intel Thermal Velocity Boost feature by ensuring best-case operating temperatures.
intel cryo cooling key features & benefits

Note that the Peltier element will dump additional heat in your water loop, so ensure you use an appropriate radiator size. Also, check if the cooler and controller are compatible with your motherboard and chassis, as there may be some incompatibility issues, as Der8auer highlighted in his video.

EK-Quantum Surface P480M

I added an extra radiator in the water loop just in case the additional 200W heat of the TEC, combined with the heat from the Core i9-13900K P-core, would saturate the cooling solution. I had previously experienced such issues in SkatterBencher #36. Furthermore, since I reached a water temperature of 40C in SkatterBencher #49 with the 13900K, I figured it was good to plan just in case.

Intel Core i9-13900K P-core: Benchmark Software

We use Windows 11 and the following benchmark applications to measure performance and ensure system stability.

13900k p-core benchmark applications

Since we’re focusing on P-core overclocking, I will disable the E-cores for all configurations.

Intel Core i9-13900K P-core: Stock Performance

Before starting overclocking, we must check the system performance at default settings. To get that information, we need to disable the E-cores and correctly configure the Turbo Boost 2.0 parameters. That’s because the Maximus Z790 Apex fully unleashes the Turbo Boost 2.0 power limits out of the box. So, to check the performance at default settings, you must enter the BIOS and

  • Go to the Extreme Tweaker menu
  • Set ASUS MultiCore Enhancement to Disabled – Enforce All Limits
  • Go to the Advanced menu
  • Enter the CPU Configuration submenu
    • Set Active Efficiency Cores to 0

Then save and exit the BIOS. Ensure the Cryo Cooling mode is set to Cryo in the operating system.

Here is the benchmark performance at stock:

  • SuperPI 4M: 26.816 seconds
  • Geekbench 5 (single): 2,240 points
  • Geekbench 5 (multi): 15,203 points
  • Cinebench R23 Single: 2,234 points
  • Cinebench R23 Multi: 20,234 points
  • CPU-Z V17.01.64 Single: 869.5 points
  • CPU-Z V17.01.64 Multi: 9,104.6 points
  • V-Ray 5: 16,360 vsamples
  • AI Benchmark: 4,961 points
  • 3DMark Night Raid: 71,950 points
  • CS:GO FPS Bench: 662.78 fps
  • Tom Raider: 202 fps
  • Final Fantasy XV: 201.02 fps
13900k p-core stock benchmark performance

Here are the 3DMark CPU Profile scores at stock

  • CPU Profile 1 Thread: 1,236
  • CPU Profile 2 Threads: 2,427
  • CPU Profile 4 Threads: 4,677
  • CPU Profile 8 Threads: 8,650
  • CPU Profile 16 Threads: 10,691
  • CPU Profile Max Threads: 10,664
13900k p-core stock cpu profile performance

When running Prime 95 Small FFTs with AVX2 enabled, the average CPU P-core clock is 5321 MHz with 1.127 volts. The average CPU temperature is 100 degrees Celsius. The water temperature is 38.0 degrees Celsius. The average CPU package power is 221.2 watts.

13900k p-core stock prime95 avx

When running Prime 95 Small FFTs with AVX disabled, the average CPU P-core clock is 5500 MHz with 1.19 volts. The average CPU temperature is 93 degrees Celsius. The water temperature is 36.8 degrees Celsius. The average CPU package power is 203.8 watts.

13900k p-core stock prime95 non-avx

Now, let us try our first overclocking strategy.

However, before we get going, make sure to locate the CMOS Clear button

Pressing the Clear CMOS button will reset all your BIOS settings to default which is helpful if you want to start your BIOS configuration from scratch. However, it does not delete any of the BIOS profiles previously saved. The Clear CMOS button is located on the rear IO panel.

OC Strategy #1: Unleashed Turbo Boost 2.0 + XMP 3.0

In our first overclocking strategy, we take advantage of unleashing the Turbo Boost 2.0 power limits and Intel XMP 3.0.

Turbo Boost 2.0 Technology

Intel Turbo Boost 2.0 Technology allows the processor cores to run faster than the base operating frequency. Turbo Boost is available when the processor works below its rated power, temperature, and current specification limits. The ultimate advantage is opportunistic performance improvements in both multi-threaded and single-threaded workloads.

The turbo boost algorithm works according to a proprietary EWMA formula which stands for Exponentially Weighted Moving Average. There are three parameters to consider: PL1, PL2, and Tau.

  • Power Limit 1, or PL1, is the threshold the average power won’t exceed. Historically, this has always been set equal to Intel’s advertised TDP. PL1 should not be set higher than the thermal solution cooling limits.
  • Power Limit 2, or PL2, is the maximum power the processor can use for a limited amount of time.
  • Tau, in seconds, is the time window for calculating the average power consumption. The CPU reduces the CPU frequency if the average power consumed is higher than PL1.
turbo boost 2.0 ewma

Adjusting the power limits is, strictly speaking, not considered overclocking, as we don’t change any of the CPU’s thermal, electrical, or frequency parameters. Intel provides the Turbo Boost parameters as guidance to motherboard vendors and system integrators to ensure their designs enable the base performance of the CPU. Better motherboard designs, thermal solutions, and system configurations can facilitate peak performance for longer.

Intel Extreme Memory Profile 3.0

Intel Extreme Memory Profile, or XMP, is an Intel technology that lets you automatically overclock the system memory to improve system performance. It extends the standard JEDEC specification and allows a memory vendor to program different settings onto the memory stick.

Intel Extreme Memory Profile 3.0 is the new XMP standard for DDR5 memory. It is primarily based on the XMP 2.0 standard for DDR4 but has additional functionality.

xmp 3.0

There’s a lot more to the new XMP 3.0 standard, which is outside the scope of this overclocking guide. If you’re interested in more details about XMP 3.0, check out my Alder Lake launch article.

BIOS Settings & Benchmark Results

Upon entering the BIOS

  • Go to the Extreme Tweaker menu
  • Set AI Overclock Tuner to XMP II
  • Set ASUS MultiCore Enhancement to Enabled – Remove All Limits
  • Go to the Advanced menu
  • Enter the CPU Configuration submenu
    • Set Active Efficiency Cores to 0

Then save and exit the BIOS. Ensure the Cryo Cooling mode is set to Cryo in the operating system.

We re-ran the benchmarks and checked the performance increase compared to the default operation.

  • SuperPI 4M: +1.18%
  • Geekbench 5 (single): +1.74%
  • Geekbench 5 (multi): +10.91%
  • Cinebench R23 Single: +0.09%
  • Cinebench R23 Multi: +13.33%
  • CPU-Z V17.01.64 Single: +1.50%
  • CPU-Z V17.01.64 Multi: +0.11%
  • V-Ray 5: +1.89%
  • AI Benchmark: +10.28%
  • 3DMark Night Raid: +1.26%
  • CS:GO FPS Bench: +0.76%
  • Tomb Raider: +0.99%
  • Final Fantasy XV: +0.04%
13900k p-core mce xmp benchmark performance

Here are the 3DMark CPU Profile scores

  • CPU Profile 1 Thread: +0.57%
  • CPU Profile 2 Threads: +0.91%
  • CPU Profile 4 Threads: +0.13%
  • CPU Profile 8 Threads: +1.60%
  • CPU Profile 16 Threads: +0.21%
  • CPU Profile Max Threads: +0.09%
13900k p-core mce xmp cpu profile performance

As expected, since we’re not increasing the frequency of the CPU cores, the performance improvement is limited to the power-hungry benchmarks. Additionally, improving the memory performance by using XMP 3.0 does help in memory-sensitive benchmark applications. We see the highest performance improvement of +13.33% in Cinebench R23.

When running Prime 95 Small FFTs with AVX2 enabled, the average CPU P-core clock is 5291 MHz with 1.121 volts. The average CPU temperature is 100 degrees Celsius. The water temperature is 37.2 degrees Celsius. The average CPU package power is 222.5 watts.

13900k p-core mce xmp prime95 avx

When running Prime 95 Small FFTs with AVX disabled, the average CPU P-core clock is 5499 MHz with 1.192 volts. The average CPU temperature is 98 degrees Celsius. The water temperature is 36.6 degrees Celsius. The average CPU package power is 213.4 watts.

13900k p-core mce xmp prime95 non-avx

OC Strategy #2: AI Overclocking + XMP Tweaked

In our second overclocking strategy, we use the Asus AI Overclocking and XMP Tweaked features integrated into the ASUS ROG BIOS.

ASUS AI Overclocking

ASUS AI overclocking uses a unique strategy for automatic overclocking. Instead of working with preset frequency and voltage profiles, the system will monitor the CPU and cooling system throughout an initial testing phase. Based on its findings, it will then predict the optimal settings. The system will automatically guide the overclocking process and adjust voltages and frequency to match your cooling system.

The better your cooling, the higher your AI overclock.

asus z790 ai overclocking

There are three steps to enabling AI overclocking. First, reset the BIOS to default settings. Then, reboot and enter the operating system. Run a couple of heavy workloads, such as Cinebench R23, Realbench, or Intel XTU, for 10 to 30 minutes. Then return to the BIOS and enter the AI OC Guide menu from the top. Make sure to read through the explanation and click Enable AI when ready.

In addition to automatic overclocking, AI Overclocking provides a lot of advanced information and suggestions in the AI Features menu. The information includes:

  • P0 VID and SP values for the P-cores and E-cores
  • Turbo Ratio suggested overclocking parameters
  • Adaptive Voltage and AC loadline suggested parameters

The SP value is based on the combination of maximum boost frequency, temperature, and P0 VID. Generally, it indicates the quality of a particular core. A higher SP value would indicate a better-quality core with superior overclocking capabilities, though it’s not an exact science. The overclocking suggestions are based on a continued evaluation of your CPU thermal solution.

13900k p-core sp rating

There are a couple of additional options to finetune the AI Overclock configuration, including two we’ll use in this configuration: Optimized AVX Frequency and Optimism Scale.

Optimized AVX Frequency allows you to toggle between Normal Use and Heavy Use, where Heavy Use should be selected if you’re running extreme workloads like Prime95 with AVX enabled.

asus ai overclocking optized avx frequency

The Optimism Scale can offset the overclocking predictions. If you set a value higher than 100, you tell the algorithm the cooler is better than estimated. So, the frequencies will be higher. Conversely, when you set a value lower than 100 because the algorithm overestimated the quality of the cooler, then the frequencies will be slightly lower.

ai overclocking optimism scale

After enabling AI Overclock and adjusting the Optimized AVX Frequency and Optimism Scale, the following settings have changed:

13900k p-core ai overclocking settings

Package Temperature Threshold

I briefly covered this feature in the Alder Lake launch article and SkatterBencher #25 with the Core i9-11900K.

This feature allows you to configure a maximum temperature for the CPU. The ASUS motherboard will track the CPU temperature during operation. Once the temperature exceeds your target temperature, the CPU frequency will be reduced. It does this not directly by adjusting the CPU ratio but by adjusting the Turbo Boost power limit parameters. By lowering the power limits, the Intel CPU will change the CPU ratio down on its own.

When you enable AI Overclocking, this feature is automatically enabled and set to 90 degrees Celsius.

XMP Tweaked

XMP Tweaked is a new option available under Ai Overclock Tuner in addition to XMP I and XMP II. All three settings load the memory kit XMP profile, but do it slightly differently.

  • XMP I loads only the primary timings, frequency, and voltage. The secondary timings are adjusted by the motherboard auto-rules
  • XMP II loads the complete XMP profile, including the primary and secondary timings, the memory frequency, and the voltage.
  • XMP Tweaked loads the complete XMP profile and makes further adjustments to various timings if possible

In this OC Strategy, I try XMP Tweaked instead of the XMP II I usually use.

BIOS Settings & Benchmark Results

Upon entering the BIOS

  • Enter the AI OC Guide
    • Press Enable AI
  • Go to the Extreme Tweaker menu
  • Set AI Overclock Tuner to XMP Tweaked
  • Set ASUS MultiCore Enhancement to Enabled – Remove All Limits
  • Set Optimized AVX Frequency to Heavy AVX
  • Enter the AI Features submenu
    • Set Optimism Scale to 95
  • Go to the Advanced menu
  • Enter the CPU Configuration submenu
    • Set Active Efficiency Cores to 0

Then save and exit the BIOS. Ensure the Cryo Cooling mode is set to Cryo in the operating system.

We re-ran the benchmarks and checked the performance increase compared to the default operation.

  • SuperPI 4M: +6.84%
  • Geekbench 5 (single): +8.04%
  • Geekbench 5 (multi): +15.17%
  • Cinebench R23 Single: +4.79%
  • Cinebench R23 Multi: +15.59%
  • CPU-Z V17.01.64 Single: +5.18%
  • CPU-Z V17.01.64 Multi: +2.15%
  • V-Ray 5: +5.35%
  • AI Benchmark: +11.65%
  • 3DMark Night Raid: +3.37%
  • CS:GO FPS Bench: +1.32%
  • Tomb Raider: +1.49%
  • Final Fantasy XV: +1.37%
13900k p-core ai overclocking benchmark performance

Here are the 3DMark CPU Profile scores

  • CPU Profile 1 Thread: +3.56%
  • CPU Profile 2 Threads: +4.90%
  • CPU Profile 4 Threads: +5.32%
  • CPU Profile 8 Threads: +4.43%
  • CPU Profile 16 Threads: +4.27%
  • CPU Profile Max Threads: +4.44%
13900k p-core ai overclocking cpu profile performance

With AI Overclocking, we increase the processor frequency from 5.8 GHz stock frequency to 6.0 GHz and higher. Therefore, we expect a performance uplift, which we also see in the benchmark results. The performance uplift from AI Overclocking is surprisingly good. We have the best performance improvement of +15.59% in Cinebench R23.

When running Prime 95 Small FFTs with AVX2 enabled; unfortunately, the CPU is not stable. That’s not surprising since AI Overclock is designed for typical workload scenarios and not extreme workloads like Prime95 with AVX2 enabled.

When running Prime 95 Small FFTs with AVX disabled, the average CPU P-core clock is 5600 MHz with 1.148 volts. The average CPU temperature is 84 degrees Celsius. The water temperature is 33.8 degrees Celsius. The average CPU package power is 191.0 watts.

13900k p-core ai overclocking prime95 non-avx

OC Strategy #3: Manual Overclock

In our third overclocking strategy, we will pursue a manual overclock. The approach is based mainly on tuning the Turbo Ratio configuration and adjusting the adaptive voltage. As I mentioned at the beginning of this article, I assume you’re already familiar with the basics of Intel CPU overclocking. So, I will skip over explaining how overclocking works and go straight to the configuration notes.

Turbo Ratio Configuration

I can be short about the Turbo Ratio configuration as we keep it pretty simple in this OC Strategy. I set the by core usage configuration such that the P-cores can boost to 6.2 GHz when up to 4 cores are active, boost to 6.0 GHz when up to 6 cores are active, and boost to 5.9 GHz when all cores are active.

13900k p-core manual overclock turbo ratio configuration

That provides us with a boost over stock of about 400 MHz for single-threaded workloads and 400 MHz in all core workloads

Intel Adaptive Voltage

In previous Raptor Lake SkatterBencher guides, I’ve discussed using Intel Adaptive Voltage mode to configure the CPU core voltage. While I won’t get into the details, I will quickly go over the basics as it’s helpful to understand the configuration for this OC Strategy.

VccIA Voltage Rail

On Raptor Lake, the VccIA voltage rail drives the voltage for the CPU cores, P-core and E-core, and the Ring. That means a single voltage is used for all these parts of the CPU. How that voltage is configured is straightforward yet complex. There are three key aspects to understanding how voltage is configured on Intel platforms: the CPU, the motherboard design, and the voltage regulator. Let’s start with the CPU side of the story.

V/F Curves

An Intel CPU relies on many factory-fused voltage-frequency curves, or V/F curves, to regulate its dynamic compute performance behavior. A V/F curve describes the relationship between an operating frequency and the voltage required for that frequency. Many parts inside your CPU have a V/f curve, including those relevant to the VccIA voltage rail. In this case, since we’re disabling the E-cores, there are 9 V/F curves affecting the voltage rail.

  • Each of the 8 P-cores
  • The ring

Based on these V/F curves, to get a specific voltage provided via the VccIA voltage rail, the CPU issues an SVID request to the voltage controller. The VID requested is the highest among all the requested voltages according to every V/F curve affecting the voltage rail.

raptor lake vf curve

The goal of the SVID voltage request from the CPU to the voltage regulator is that the effective voltage at the CPU die is equal to the requested voltage. However, as overclockers and enthusiasts know very well, that’s not always the case. That’s because there are a lot of electrical components between the voltage regulator and the CPU die.

To avoid the voltage delivered to the CPU die being lower than the requested voltage, we have two main tools: (1) AC-DC loadline and (2) VRM loadline.

AC DC Loadline

The AC DC loadline is designed for motherboard engineers to bring into the voltage-frequency curve equation the electrical impedance of the motherboard design. Electrical impedance is the opposition to alternating current and is affected by the VRM components, the PCB layout, and quality.

Electrical impedance can significantly affect the effective voltage at the CPU die. Therefore, there may be a significant difference between the requested and effective voltage. We can define the AC DC loadline parameters to account for this difference.

Adjusting the AC loadline offsets the requested voltage, defined by the factory-fused voltage-frequency curve, to account for any electrical impedance.

Adjusting the DC loadline informs the CPU power control unit about the expected effective voltage at the CPU die. On the Maximus Z790 Apex, the DC loadline is synced with the VRM loadline, so there’s no need to manually adjust this value.

Before we look at how to set up the AC DC loadline, we must talk about the VRM loadline.

VRM loadline

The VRM loadline is essential for two reasons: the Vdroop and undershoot.

Vdroop is the decrease in voltage when the CPU goes from idle to load. You want your CPU to be stable in all scenarios, so knowing the lowest voltage the CPU runs at is very important. After all, if the voltage is too low, the overclock won’t be stable.

Undershoot and its counterpart, overshoot, is a brief voltage spike that occurs when the CPU switches from idle to load or from load to idle. These spikes cannot be measured easily and usually require an expensive oscilloscope to detect. I highly recommend the ElmorLabs article titled VRM Load-Line Visualized to see a great picture of undershoot and overshoot in action.

While undershoot and overshoot are temporary spikes, an undershoot that’s too low can cause instability.

raptor lake vrm loadline

The VRM loadline setting is relevant to our overclock in two ways.

  • It helps control the voltage in heavy workloads. Enthusiasts often rely on VRM loadline tuning to decrease the voltage in a heavy workload, which yields lower power consumption and operating temperatures.
  • Since the VRM loadline can significantly affect the effective CPU core voltage, we must account for it when setting the DC loadline.

Advanced Voltage Offset – V/F Points

Advanced voltage offset, or V/F Points, is an extension of the Adaptive Voltage as it exposes some of the points on the V/f curve to the end-user and allows for manual adjustment of these points.

When we set an adaptive voltage in the BIOS, it is mapped against the “OC Ratio.” Unless explicitly programmed, the OC Ratio is the highest ratio configured for the CPU across all settings, including by core usage, per core ratio limit, and OCTVB. In this OC Strategy, that would be 62X. The voltage for ratios lower than the OC ratio is set either by its factory-fused V/f point or, if there’s no V/f point, interpolated between the next and previous V/f point.

raptor lake adaptive voltage

The primary purpose of the Advanced Voltage Offset is to provide end-users with the ability to under-volt their CPUs at specific points of the V/f curve. In addition to undervolting, this feature also allows overvolting.

Overclockers commonly use the Advanced Voltage Offset function in two ways.

  1. You configure a positive voltage offset for the highest V/f point, which helps achieve a higher single-threaded boost frequency.
  2. You configure a negative voltage offset for the second-highest V/f point. That helps achieve lower voltage for all-core boost, which results in a lower temperature in all-core boost, and thus potential additional overclocking headroom.

On Raptor Lake, there are 15 distinct voltage-frequency points. However, only points one to eleven are used. Furthermore, some points can be copies of other points. On the 13900K, the V/F points are as follows:

13900k v/f points

Unfortunately, it looks like the implementation of the V/F Points is not mature yet. There are quite a few issues when using it for a daily overclock. Two problems, in particular, can be frustrating:

  1. Sometimes the V/F Points don’t work correctly in combination with 100 MHz BCLK. An easy workaround is to have the BCLK frequency slightly lower or higher than 100 MHz.
  2. Sometimes programming V/F Point 9 conflicts with V/F Point 10. The easy workaround is to program both V/F Points to the same value.

Also, sometimes motherboards have auto-rules that automatically set an adaptive voltage when end-users set high CPU ratios. It’s important to know that V/F Point 11 adds to the adaptive voltage. If you’re not careful and leave the adaptive voltage set at Auto, you may end up with really high voltage. The easy workaround here is to set the adaptive voltage manually.

Voltage Configuration

I felt it was necessary to detail how adaptive voltage works to add context to the specific configuration of this OC Strategy. Some may call it a “purist” approach because I wanted the voltage to follow the V/F curve as closely as possible. Hence, I opted for an AC loadline of 0.01 and a VRM loadline of level 8.

Sidenote: generally, I do not recommend a VRM loadline of level 8 as it can induce nasty overshoot spikes. With ASUS’ VLatch function, you can actually check the overshoot, and it seemed that the overshoot spike for this specific 8 P-core platform, even with VRM loadline level 8, was reasonable.

As for the V/F Points: I could substantially undervolt V/F Points 6 to 9 to achieve lower voltage in all-core workloads and thus saw a nice boost in all-core load frequency. In Prime95 small FFTs with AVX disabled, the average P-core frequency increased from 5500 MHz to 5752 MHz. For the maximum boost frequency of 6.2 GHz, I set an adaptive voltage of 1.425V.

13900k p-core manual overclock voltage configuration

As a result, the final voltage-frequency curve for this OC Strategy looks as follows.

13900k p-core manual overclock v/f curve

Other Tuning

In addition to the Turbo Ratio and voltage configuration, we make several other minor adjustments to our overclock.

BCLK Frequency

We set the BCLK frequency to 100.15 MHz to work around a potential issue with the configuration of the V/F points.

AVX Negative Ratio Offset

We set an AVX negative ratio offset of 4, reducing the CPU frequency in some AVX workloads. While AVX negative ratio offset has been on Intel CPUs for ages, since Alder Lake, there have been a couple of changes in the behavior. I discussed that in previous Raptor Lake guides. The long story short is that the AVX offset doesn’t apply to all AVX workloads, such as Cinebench R23.

Thermal Velocity Boost Voltage Optimizations

Thermal velocity boost is an Intel technology that exploits the fact that CPUs need less voltage to run a specific frequency when the operating temperature is lower. As we want manual control over the operating voltage to ensure stability, it’s prudent to disable this function.

Manual Memory Overclocking

In addition to CPU overclocking, I also wanted to push the memory further. While I didn’t quite hit my target of DDR5-8000, I was able to further increase the memory frequency to DDR5-7600 with the kit’s XMP timings and slightly elevated voltage of 1.45V

BIOS Settings & Benchmark Results

Upon entering the BIOS

  • Go to the Advanced menu
    • Enter the CPU Configuration submenu
      • Set Active Efficiency Cores to 0
  • Go to the Extreme Tweaker menu
  • Set AI Overclock Tuner to XMP II
  • Set BCLK Frequency to 100.15
  • Set ASUS MultiCore Enhancement to Enabled – Remove All Limits
  • Set DRAM Frequency to DDR5-7615MHz
  • Set Performance Core Ratio to By Core Usage
    • Set 1-Core to 4-Core Ratio Limit to 62
    • Set 5-Core and 6-Core Ratio Limit to 60
    • Set 7-Core and 8-Core Ratio Limit to 59
  • Enter the AVX Related Controls submenu
    • Set AVX2 Ratio Offset to per-core Ratio Limit to User Specify
    • Set AVX2 Ratio Offset to 4
  • Leave the AVX Related Controls submenu
  • Enter the DIGI+ VRM submenu
    • Set CPU Load-line Calibration to Level 8
  • Leave the DIGI+ VRM submenu
  • Enter the Internal CPU Power Management submenu
    • Set Regulate Frequency by above Threshold to Disabled
    • Set IA AC Load Line to 0.01
  • Leave the Internal CPU Power Management submenu
  • Enter the Thermal Velocity Boost submenu
    • Set TVB Voltage Optimizations to Disabled
  • Leave the Thermal Velocity Boost submenu
  • Enter the V/F Point Offset submenu
    • Set Offset Mode Sign 6 to 10 to –
    • Set V/F Point 6 to 0.100
    • Set V/F Point 7 to 0.135
    • Set V/F Point 8, 9, and 10 to 0.150
  • Leave the V/F Point Offset submenu
  • Set Global Core SVID Voltage to Adaptive Mode
    • Set Offset Mode Sign to +
    • Set Additional Turbo Mode CPU Core Voltage to 1.425
  • Set High DRAM Voltage Mode to Enabled
  • Set DRAM VDD Voltage to 1.45
  • Set DRAM VDDQ Voltage to 1.45

Then save and exit the BIOS. Ensure the Cryo Cooling mode is set to Cryo in the operating system.

We re-ran the benchmarks and checked the performance increase compared to the default operation.

  • SuperPI 4M: +7.98%
  • Geekbench 5 (single): +10.71%
  • Geekbench 5 (multi): +17.12%
  • Cinebench R23 Single: +6.94%
  • Cinebench R23 Multi: +20.02%
  • CPU-Z V17.01.64 Single: +14.34%
  • CPU-Z V17.01.64 Multi: +8.06%
  • V-Ray 5: +9.60%
  • AI Benchmark: +14.29%
  • 3DMark Night Raid: +7.79%
  • CS:GO FPS Bench: -2.39%
  • Tomb Raider: +2.48%
  • Final Fantasy XV: +3.11%
13900k p-core manual overclock benchmark performance

Here are the 3DMark CPU Profile scores

  • CPU Profile 1 Thread: +6.47%
  • CPU Profile 2 Threads: +8.12%
  • CPU Profile 4 Threads: +8.83%
  • CPU Profile 8 Threads: +9.42%
  • CPU Profile 16 Threads: +5.87%
  • CPU Profile Max Threads: +6.65%
13900k p-core manual overclock cpu profile performance

We increase the P-core frequency by a modest 400 MHz for single-threaded workloads and all core workloads. That provides us with an also modest performance improvement across the board and an impressive +20% in Cinebench R23 multi. Unfortunately, the CS:GO performance dropped about 2% after switching to a manual BCLK frequency. While I could isolate the performance issue to the BCLK frequency, I could not figure out how to solve this issue.

When running Prime 95 Small FFTs with AVX2 enabled, the average CPU P-core clock is 5162 MHz with 1.143 volts. The average CPU temperature is 100 degrees Celsius. The water temperature is 35.3 degrees Celsius. The average CPU package power is 228.6 watts.

13900k p-core manual overclock prime95 avx

When running Prime 95 Small FFTs with AVX disabled, the average CPU P-core clock is 5752 MHz with 1.193 volts. The average CPU temperature is 100 degrees Celsius. The water temperature is 32.3 degrees Celsius. The average CPU package power is 224.6 watts.

13900k p-core manual overclock prime95 non-avx

OC Strategy #4: OCTVB

In our fourth overclocking strategy, we resort to advanced manual tuning with OCTVB to squeeze more performance out of our system. We have two objectives:

  1. We want to use OCTVB to squeeze more frequency out of the chip and provide higher performance in light workloads.
  2. We want to use Cache Dynamic OC Switcher to improve the CPU frequency in heavy all-core workloads.

OCTVB – OverClocking Thermal Velocity Boost

In 2018 Intel introduced Thermal Velocity Boost along with the Core i9-8950HK Coffee Lake mobile flagship processor, and it’s since been an indispensable feature on Intel Core processors.

Thermal Velocity Boost does two things.

  1. First, it decreases the operating voltage if the CPU temperature is below the TjMax.
  2. Two, it opportunistically increases the clock frequency above the Turbo Boost 2.0 and 3.0 frequencies based on how much the processor operates below its maximum temperature.

With the introduction of the Intel Cryo Cooling Technology in 2020, Intel opened up the TVB configuration to motherboard vendors. The feature is named OverClocking Thermal Velocity Boost, or OCTVB for short.

The easiest way to think of OCTVB is limiting, or clipping, the maximum allowed CPU ratio based on the CPU operating temperature. The hotter the CPU, the more you clip the CPU ratio. OCTVB is based on the by core usage Turbo Ratio configuration. For each number of active cores, you can define two temperature points, each with a unique number of “down-bins’. A down-bin is essentially the number of ratios you want to drop.

Let’s take the configuration of this OC Strategy.

13900k p-core octvb configuration

When 1 P-core is active, the base ratio is 64X, so the frequency will be 6.4 GHz. However, when the temperature is 65 degrees Celsius, the ratio is clipped by 1X. That means the maximum ratio is now 63X.

When all 8 P-cores are active, the base ratio is 62X, so the frequency will be 6.2 GHz. However, when the temperature is 65 degrees Celsius, the ratio is clipped by 2X. That means the maximum ratio is now 60X. When the temperature hits 90 degrees Celsius, the ratio is clipped once more by 1X. So, the resulting maximum ratio is now 59X.

Note that we have TjMax configured at the default of 100 degrees Celsius. So beyond 100 degrees Celsius, the CPU will automatically reduce the frequency to stay within the thermal limit.

Testing an OCTVB configuration is notoriously tricky because you can’t simply stress-test as you’d typically do. So, most of OCTVB validation is just running your benchmark test suite to see if there are any instabilities. Still, as I’ve demonstrated in previous SkatterBencher guides, we can leverage the Thermal Velocity Boost Voltage Optimizations feature to get a rough idea of how many extra bins we can get with lower temperatures.

raptor lake thermal velocity boost voltage optimization

ASUS Cache Dynamic OC Switcher

Dynamic OC Switcher is a notable feature on ASUS AMD motherboards. It was first introduced on the Crosshair VIII Dark Hero motherboard, and I first showed how it worked in SkatterBencher #15.

On AMD platforms, Dynamic OC Switcher allows at-runtime switching between OC and PBO modes to maximize the overclocking for single-core and all-core workloads. Cache Dynamic OC Switcher is similar in that it enables at-runtime switching at a specific trigger point. However, as the name already implies, this is not to switch for CPU frequency optimization but for Ring performance optimization. Here’s how it works.

You define two so-called “gears,” high and low gear, and a trigger switching point. The trigger is the CPU current. Anything above the set threshold triggers low gear, and everything below the threshold activates high gear. Practically, low gear represents an all-core load, while high gear represents a light or few-threaded workload.

asus cache dynamic oc switcher
  • In high gear, you can define 3 parameters: the Ring ratio, the Ring voltage, and the number of threads to go to sleep.
  • In low gear, you define 2 parameters: the Ring Ratio and the Ring Voltage.

The motherboard will force several CPU threads to sleep when the high gear is activated. The threads are disabled in priority with the hyperthreads first, then the E-cores, then the P-cores.

Suppose you’re using a Core i9-13900K and want only “real” P-cores to be used in high gear mode. In that case, you’d set the number of threads to sleep to 24, as this will include the 8 13900K P-core hyperthreads and the 16 E-cores.

asus cache dynamic oc switcher configuration

The main reason why this feature exists is that the Ring is stable at higher frequencies when only 13900K P-cores are active compared to when both P- and E-cores are active. However, in this strategy, we use it for a different purpose.

Attentive viewers will have noticed something strange with the Prime95 results of OC Strategy #1 and #3: While the frequency increased in the non-AVX workload from 5500 MHz to 5750 MHz, the frequency in the AVX-enabled workload actually decreased from 5291 MHz to 5162 MHz!

What happened? To make a long story short: V/F curves happened.

As I explained before, the VccIA voltage rail drives the voltage for the CPU P-cores, E-cores, and Ring, and the voltage requested by the CPU is the highest among all associated V/F curves.

The Ring frequency drops to 4500 MHz in an all-core workload on this system. When we look at the Ring V/F curve, we see that the voltage associated with 45X is 1.14V. When we look at the default P-core V/F curve, we see that the voltage for 51X and 52X are 1.15V and 1.17V, respectively.

So, in an all-core workload with a CPU frequency of 5.2 GHz and a Ring frequency of 4.5 GHz, the VccIA voltage is determined by the P-cores MAX(1.17, 1.14)=1.17V.

However, after the undervolting from OC Strategy #3, we find that the voltage for 51X and 52X are now 1.05 and 1.06V.

So, in the same situation, the VccIA voltage is now determined by the Ring MAX(1.06, 1.14)=1.14V. So, effectively, the voltage provided to the P-cores is higher than needed for that frequency.

To make matters worse, for a Prime95 AVX workload with this CPU and cooler, the maximum voltage to reach TjMax is about 1.12 to 1.13V. So, the Ring V/F Point of 1.14V at 45X pushes the CPU temperature over TjMax. As a response, the CPU will reduce the P-core frequency to stay below TjMax.

Ordinarily, the only option would be to restrict the Ring frequency to 43X or 44X. That’s possible with the available BIOS options. But with Ring DOS, we can have the best of both worlds: 5 GHz Ring in most workloads and less than 4.5 GHz Ring in extreme workloads.

As a sidenote, there are actually also Ring V/F points available on Raptor Lake. However, these are not exposed in any BIOSes. If we would have access to the Ring V/F Points, we’d possibly be able to use these as well for solving this challenge.

core i9-13900k ring v/f points

In my configuration, I set the switching threshold to 160A, the number of threads to sleep to 0, the high gear ratio to 50X, and the low gear ratio to 44X. As you’ll see in the Prime95 results, that helps improve the AVX-enabled P-core frequency from 5162 MHz to 5434 MHz.

cache dynamic oc switcher z790 apex bios

BIOS Settings & Benchmark Results

Upon entering the BIOS

  • Go to the Advanced menu
    • Enter the CPU Configuration submenu
      • Set Active Efficiency Cores to 0
  • Go to the Extreme Tweaker menu
  • Set AI Overclock Tuner to XMP II
  • Set BCLK Frequency to 100.15
  • Set ASUS MultiCore Enhancement to Enabled – Remove All Limits
  • Set DRAM Frequency to DDR5-7615MHz
  • Set Performance Core Ratio to By Core Usage
    • Set 1-Core to 3-Core Ratio Limit to 64
    • Set 4-Core Ratio Limit to 63
    • Set 5-Core to 8-Core Ratio Limit to 62
  • Enter the Specific Performance Core submenu
    • Set Performance Core2 and Core6 Specific Ratio Limit to 63
    • Set Performance Core2 and Core6 Specific Voltage to Adaptive Mode
      • Set Offset Mode Sign to +
      • Set Additional Turbo Mode CPU Core2 and Core6 Voltage to 1.5
  • Leave the Specific Performance Core submenu
  • Enter the AVX Related Controls submenu
    • Set AVX2 Ratio Offset to per-core Ratio Limit to User Specify
    • Set AVX2 Ratio Offset to 6
  • Leave the AVX Related Controls submenu
  • Enter the DIGI+ VRM submenu
    • Set CPU Load-line Calibration to Level 8
  • Leave the DIGI+ VRM submenu
  • Enter the Internal CPU Power Management submenu
    • Set Regulate Frequency by above Threshold to Disabled
    • Set IA AC Load Line to 0.01
  • Leave the Internal CPU Power Management submenu
  • Enter the Thermal Velocity Boost submenu
    • Set Cache Dynamic OC Switcher to Enabled
      • Set Current Threshold to Switch to Low Cache Gear to 160
      • Set Threads to Sleep for High Cache Gear to 0
      • Set High Cache Ratio to 50
      • Set Low Cache Ratio to 44
    • Set TVB Voltage Optimizations to Disabled
    • Set Overclocking TVB to Enabled
      • Set 1-Core to 8-Core Active to Enabled
      • For each Core Active, set Temperature A to 65
      • For each Core Active, set Negative Ratio Offset A to User Specify
      • For 1-Core to 6-Core Active, set Ratio Offset A to 1
      • For 7-Core and 8-Core Active, set Ratio Offset A to 2
      • For 1-Core to 4-Core Active, set Temperature B to 80
      • For 5-Core and 6-Core Active, set Temperature B to 85
      • For 7-Core and 8-Core Active, set Temperature B to 90
      • For each Core Active, set Negative Ratio Offset B to User Specify
      • For each Core Active, set Ratio Offset B to 1
  • Leave the Thermal Velocity Boost submenu
  • Enter the V/F Point Offset submenu
    • Set Offset Mode Sign 6 to 10 to –
    • Set V/F Point 6 to 0.100
    • Set V/F Point 7 to 0.135
    • Set V/F Point 8, 9, and 10 to 0.150
  • Leave the V/F Point Offset submenu
  • Set Global Core SVID Voltage to Adaptive Mode
    • Set Offset Mode Sign to +
    • Set Additional Turbo Mode CPU Core Voltage to 1.5
  • Set High DRAM Voltage Mode to Enabled
  • Set DRAM VDD Voltage to 1.45
  • Set DRAM VDDQ Voltage to 1.45

Then save and exit the BIOS. Ensure the Cryo Cooling mode is set to Cryo in the operating system.

We re-ran the benchmarks and checked the performance increase compared to the default operation.

  • SuperPI 4M: +9.88%
  • Geekbench 5 (single): +13.13%
  • Geekbench 5 (multi): +19.67%
  • Cinebench R23 Single: +9.13%
  • Cinebench R23 Multi: +18.83%
  • CPU-Z V17.01.64 Single: +17.14%
  • CPU-Z V17.01.64 Multi: +8.74%
  • V-Ray 5: +9.68%
  • AI Benchmark: +16.00%
  • 3DMark Night Raid: +7.71%
  • CS:GO FPS Bench: -2.24%
  • Tomb Raider: +2.48%
  • Final Fantasy XV: +3.64%
13900k p-core octvb benchmark performance

Here are the 3DMark CPU Profile scores

  • CPU Profile 1 Thread: +7.36%
  • CPU Profile 2 Threads: +8.03%
  • CPU Profile 4 Threads: +9.15%
  • CPU Profile 8 Threads: +10.35%
  • CPU Profile 16 Threads: +6.98%
  • CPU Profile Max Threads: +7.56%
13900k p-core octvb cpu profile performance

While this OC strategy allows us to squeeze more frequency out of our CPU, it won’t improve the performance in all scenarios. That’s because the OCTVB leverages lower temperatures primarily. In fact, the performance improvements should only appear in light workloads such as the 3DMark CPU profile, which doesn’t push the CPU to the TjMax. We see the highest performance improvement of +19.67% in Geekbench 5 multi.

When running Prime 95 Small FFTs with AVX2 enabled, the average CPU P-core clock is 5434 MHz with 1.129 volts. The average CPU temperature is 100 degrees Celsius. The water temperature is 33.0 degrees Celsius. The average CPU package power is 230.5 watts.

13900k p-core octvb prime95 avx

When running Prime 95 Small FFTs with AVX disabled, the average CPU P-core clock is 5738 MHz with 1.193 volts. The average CPU temperature is 100 degrees Celsius. The water temperature is 33.4 degrees Celsius. The average CPU package power is 222.2 watts.

13900k p-core octvb prime95 non-avx

OC Strategy #5: Unregulated Mode

Of course, this SkatterBencher guide wouldn’t be complete if we didn’t try Unregulated mode. We aim to squeeze higher frequency out of the chip and, if possible, get a little extra performance in light workloads.

Unregulated Mode

Next to Cryo, Unregulated is one of the two available Intel Cryo Cooling Technology modes. As I mentioned at the beginning of the article, in Cryo mode, the Intel software ensures that the TEC temperature never drops below the dew point to avoid condensation.

In Unregulated mode, however, the TEC always runs at full power; thus, the temperature will drop well below ambient. You may face water droplets on your hardware without proper insulation, so be careful. Follow the Delta TEC installation guide and take all the necessary precautions to avoid condensation.

The TEC controller will flash a purple light if it’s in unregulated mode. Also, the tray icon of the Cryo Cooling software will turn white.

From an overclocker’s perspective, the Unregulated mode is helpful in two ways.

  1. It enables near or below-zero temperatures in idle. That typically allows for a higher frequency, although this is more show-off than practical use
  2. Second, it enables below-ambient temperatures in light workloads. This typically makes the same overclock in Unregulated mode more stable than cryo mode and can even slightly boost performance

Unregulated mode does not improve the overclocking experience in workloads where Cryo mode already enables the TEC to run at full power.

In my case, I use unregulated mode to increase the idle frequency to 6.5 GHz for up to 2 active P-cores.

BIOS Settings & Benchmark Results

Upon entering the BIOS

  • Go to the Advanced menu
    • Enter the CPU Configuration submenu
      • Set Active Efficiency Cores to 0
  • Go to the Extreme Tweaker menu
  • Set AI Overclock Tuner to XMP II
  • Set BCLK Frequency to 100.15
  • Set ASUS MultiCore Enhancement to Enabled – Remove All Limits
  • Set DRAM Frequency to DDR5-7615MHz
  • Set Performance Core Ratio to By Core Usage
    • Set 1-Core and 2-Core Ratio Limit to 65
    • Set 3-Core and 4-Core Ratio Limit to 64
    • Set 5-Core to 8-Core Ratio Limit to 62
  • Enter the Specific Performance Core submenu
    • Set Performance Core0, Core1, Core3, Core4, Core5, and Core7 Specific Ratio Limit to 65
    • Set Performance Core2 and Core6 Specific Ratio Limit to 64
    • Set Performance Core2 and Core6 Specific Voltage to Adaptive Mode
      • Set Offset Mode Sign to +
      • Set Additional Turbo Mode CPU Core2 and Core6 Voltage to 1.5
  • Leave the Specific Performance Core submenu
  • Enter the AVX Related Controls submenu
    • Set AVX2 Ratio Offset to per-core Ratio Limit to User Specify
    • Set AVX2 Ratio Offset to 6
  • Leave the AVX Related Controls submenu
  • Enter the DIGI+ VRM submenu
    • Set CPU Load-line Calibration to Level 8
  • Leave the DIGI+ VRM submenu
  • Enter the Internal CPU Power Management submenu
    • Set Regulate Frequency by above Threshold to Disabled
    • Set IA AC Load Line to 0.01
  • Leave the Internal CPU Power Management submenu
  • Enter the Thermal Velocity Boost submenu
    • Set Cache Dynamic OC Switcher to Enabled
      • Set Current Threshold to Switch to Low Cache Gear to 160
      • Set Threads to Sleep for High Cache Gear to 0
      • Set High Cache Ratio to 50
      • Set Low Cache Ratio to 44
    • Set TVB Voltage Optimizations to Disabled
    • Set Overclocking TVB to Enabled
      • Set 1-Core to 8-Core Active to Enabled
      • For 1-Core and 2-Core Active, set Temperature A to 35
      • For 3-Core to 8-Core Active, set Temperature A to 65
      • For each Core Active, set Negative Ratio Offset A to User Specify
      • For 1-Core, 2-Core, 7-Core, and 8-Core Active, set Ratio Offset A to 2
      • For 3-Core to 6-Core Active, set Ratio Offset A to 1
      • For 1-Core to 4-Core Active, set Temperature B to 80
      • For 5-Core and 6-Core Active, set Temperature B to 85
      • For 7-Core and 8-Core Active, set Temperature B to 90
      • For each Core Active, set Negative Ratio Offset B to User Specify
      • For each Core Active, set Ratio Offset B to 1
  • Leave the Thermal Velocity Boost submenu
  • Enter the V/F Point Offset submenu
    • Set Offset Mode Sign 6 to 10 to –
    • Set V/F Point 6 to 0.100
    • Set V/F Point 7 to 0.125
    • Set V/F Point 8 to 0.135
    • Set V/F Point 9 and 10 to 0.150
  • Leave the V/F Point Offset submenu
  • Set Global Core SVID Voltage to Adaptive Mode
    • Set Offset Mode Sign to +
    • Set Additional Turbo Mode CPU Core Voltage to 1.5
  • Set High DRAM Voltage Mode to Enabled
  • Set DRAM VDD Voltage to 1.45
  • Set DRAM VDDQ Voltage to 1.45

Then save and exit the BIOS. Ensure the Cryo Cooling mode is set to Unregulated in the operating system.

We re-ran the benchmarks and checked the performance increase compared to the default operation.

  • SuperPI 4M: +1.73%
  • Geekbench 5 (single): +13.48%
  • Geekbench 5 (multi): +21.63%
  • Cinebench R23 Single: +10.07%
  • Cinebench R23 Multi: +18.54%
  • CPU-Z V17.01.64 Single: +18.10%
  • CPU-Z V17.01.64 Multi: +10.21%
  • V-Ray 5: +11.31%
  • AI Benchmark: +16.37%
  • 3DMark Night Raid: +7.98%
  • CS:GO FPS Bench: -0.69%
  • Tomb Raider: +2.48%
  • Final Fantasy XV: +4.28%
13900k p-core unregulated benchmark performance

Here are the 3DMark CPU Profile scores

  • CPU Profile 1 Thread: +8.49%
  • CPU Profile 2 Threads: +9.64%
  • CPU Profile 4 Threads: +11.23%
  • CPU Profile 8 Threads: +11.90%
  • CPU Profile 16 Threads: +8.99%
  • CPU Profile Max Threads: +9.26%
13900k p-core unregulated cpu profile performance

The performance improvement of unregulated mode is primarily visible in the single-threaded benchmarks like SuperPI, Geekbench 5, and CPU-Z. That’s because those benchmarks would not engage the full cooling potential of the TEC in Cryo mode. We also see modest improvements across the board in the CPU Profile benchmark because it’s a relatively light workload. We see the highest performance improvement of +21.63% in Geekbench 5 Single.

When running Prime 95 Small FFTs with AVX2 enabled, the average CPU P-core clock is 5418 MHz with 1.130 volts. The average CPU temperature is 100 degrees Celsius. The water temperature is 32.6 degrees Celsius. The average CPU package power is 230.4 watts.

13900k p-core unregulated prime95 avx

When running Prime 95 Small FFTs with AVX disabled, the average CPU P-core clock is 5693 MHz with 1.200 volts. The average CPU temperature is 100 degrees Celsius. The water temperature is 32.9 degrees Celsius. The average CPU package power is 224.3 watts.

13900k p-core unregulated prime95 non-avx

Intel Core i9-13900K P-core: Conclusion

Alright, let us wrap this up.

Overclocking with the EK Delta TEC and Intel Cryo Cooling Technology is always an adventure. It makes us dream of frequencies unattainable with regular water cooling. With the 10900K, we achieved 6 GHz; with the 11900K, we achieved 5.6 GHz; and now, with the 13900K P-core, we reach an incredible 6.5 GHz. I would’ve never imagined seeing 6.5 GHz before Raptor Lake launched.

The Delta2 TEC is also surprisingly good in all-core sustained workloads as it can maintain a steady 260W CPU Package Power throughout Prime95 with all 8 P and 16 E-cores enabled.

Lastly, I was particularly excited to see that we could use ASUS’ new Ring DOS feature to extract more performance in an all-core workload. While the real-world performance gains are minimal, performance enthusiasts like me, who enjoy the “puzzle” aspect of overclocking, get excited about this stuff.

Anyway, that’s all for today! I want to thank my Patreon supporters for supporting my work. As per usual, if you have any questions or comments, feel free to drop them in the comment section below. 

See you next time!

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