SkatterBencher #26: AMD Ryzen 9 5900X Overclocked to 5223 MHz

We overclock the AMD Ryzen 9 5900X processor up to 5223 MHz with the GIGABYTE X570S Aorus Master motherboard and a Supercharged PBO.

You can supercharge PBO by increasing the base clock frequency and push the Ryzen 9 5900X up to 5.2GHz with custom loop water cooling. Though it does not exactly give you the performance you’d expect. Or you can use GIGABYTE’s Active OC Tuner to get the all the benefits from PBO and manual overclock in one configuration.

This is the first time I revisit the Ryzen 9 CPUs since the launch back in November and there is so much to talk about … so let’s get into it.

Introduction

The AMD Ryzen 9 5900X CPU launched back in November alongside its bigger and smaller brothers the 5950X and the 5800X. The 7nm 12-core CPU with a maximum listed boost frequency of up to 4.8 GHz has been quite popular among PC DIY enthusiasts.

A lot has changed since the release of the Ryzen 5000 CPUs. For overclockers, most importantly Precision Boost Overdrive 2 and Curve Optimizer gives us new avenues to squeeze more performance out of our Ryzen CPUs. Recently, AMD also provided motherboard makers with an improved X570 chipset. The new chipset no longer requires active cooling and has thus been dubbed the X570S with the S standing for Silent.

In today’s video we are pairing the GIGABYTE X570S Aorus Master with the Ryzen 9 5900X. The X570S Aorus Master is a slightly improved version of the X570 Master and is among the 4 GIGABYTE boards with an embedded controller that support Active OC Tuner. But we will do more than just that.

In this video we will cover five different overclocking strategies.

  1. First, we increase the frequency to 4950 MHz by enabling Precision Boost Overdrive and XMP
  2. Second, we manually overclock the CPU to 4550 MHz Prime 95 AVX and 4650 MHz Prime 95 non-AVX stable  
  3. Third, we leverage GIGABYTE’s Active OC Tuner to get the best of both PBO and manual overclocking modes
  4. Fourth, we push the CPU to 5125 MHz by tuning the Precision Boost Overdrive algorithm with Curve Optimizer
  5. Lastly, we achieve 5228 MHz by supercharging Precision Boost Overdrive
5900x overclocking strategies

However, before we jump into the overclocking let us quickly go over the hardware and benchmarks we use in this video.

AMD Ryzen 9 5900X X570S: Platform Overview

Along with the AMD Ryzen 9 5900X processor and GIGABYTE X570S Aorus Master motherboard, in this guide, we will be using a pair of Aorus RGB DDR4-4400 memory sticks, an NVIDIA RTX 2080TI graphics card, an 512GB Aorus RGB M.2 NVMe SSD, a Seasonic Prime 850W Platinum power supply, the ElmorLabs Easy Fan Controller, and EK-Quantum water cooling. All this is mounted on top of our favorite Open Benchtable. 

The cost of the components should be around $3,720.

  • AMD Ryzen 9 5900X processor: $570
  • EK-Quantum P360 water cooling kit: $550
  • GIGABYTE X570S Aorus Master motherboard: $390
  • NVIDIA RTX 2080 TI graphics card: $1,500
  • AORUS RGB 16GB DDR4-4400 memory: $180
  • AORUS RGB 512 GB M.2-2280 NVME: $110
  • Seasonic Prime 850W Platinum power supply: $200
  • ElmorLabs Easy Fan Controller: $20
  • Open Benchtable: $200

I covered the ElmorLabs EFC in a separate article on this website.

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. This is used for all overclocking strategies.

AMD Ryzen 9 5900X X570S: Benchmarking Software

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

The 3DMark CPU Profile benchmark is a new inclusion in the benchmark suite.

Released earlier this year in June, the 3DMark CPU Profile introduces a novel approach to CPU benchmarking. Instead of producing a single number, the 3DMark CPU Profile shows how CPU performance scales and changes with the number of cores and threads used. 

The CPU Profile has six tests, each of which uses a different number of threads. The benchmark starts by using all available threads. It then repeats using 16 threads, 8 threads, 4 threads, 2 threads, and ends with a single-threaded test.

The 3DMark CPU Profile scores are a great way to check if your CPU is performing as expected. For overclockers, the 3DMark CPU Profile shows the overclocking potential of your CPU and provides more ways to track and measure the gains from overclocking.

For AMD Ryzen systems in particular it is a useful tool as it can help detect situations where the system appears to run stably but where the effective clock is much lower than the reported frequency due to clock stretching.

For more information, you can check out the UL website: https://benchmarks.ul.com/news/new-cpu-benchmarks-for-gamers-and-overclockers

AMD Ryzen 9 5900X X570S: Stock Performance

The first thing we must do before we start any overclocking is check the system performance at default settings.

Please note that out of the box, the GIGABYTE X570S Aorus Master enables Precision Boost Overdrive. So, to check the performance at default settings you must

  • Press F2 to switch to Advanced Mode
  • Go to the Settings menu
  • Enter the AMD Overclocking submenu
    • Set Precision Boost Overdrive to Disabled

Then save and exit the BIOS.

Here is the benchmark performance at stock:

  • SuperPI 4M: 34.972 seconds
  • Geekbench 5 (single): 1,621 points
  • Geekbench 5 (multi): 12,361 points
  • HWBOT X265 4K: 24.731 fps
  • Cinebench R23 Single: 1,605 points
  • Cinebench R23 Multi: 21,491 points
  • V-Ray 5: 16,197 vsamples
  • 3DMark Night Raid: 63,427 points
  • CS:GO FPS Bench: 596.52 fps
  • Final Fantasy XV: 171.27 fps
5900x stock benchmark performance

Here are the 3DMark CPU Profile scores at stock

  • CPU Profile 1 Thread: 957
  • CPU Profile 2 Threads: 1,892
  • CPU Profile 4 Threads: 3,631
  • CPU Profile 8 Threads: 6,608
  • CPU Profile 16 Threads: 8,639
  • CPU Profile Max Threads: 9,596
5900x stock 3dmark cpu profile performance

When running Prime 95 Small FFTs with AVX enabled, the average effective CPU clock is 3703 MHz with 1.044 volts. The average CPU temperature is 63 degrees Celsius and the average CPU package power is 120 watts.

5900x stock prime95 avx

When running Prime 95 Small FFTs with AVX disabled, the average effective CPU clock is 3985 MHz with 1.128 volts. The average CPU temperature is 65 degrees Celsius and the average CPU package power is 128 watts.

5900x 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 on the back IO panel of your motherboard. In case your system fails to boot up after you configured your settings, pressing this button will force the system to reset the BIOS settings. So, you can return to the BIOS easily and make the necessary adjustments.

OC Strategy #1: Ryzen 9 5900X PBO + XMP

In our first overclocking strategy we simply take advantage of AMD’s Precision Boost Overdrive and XMP.

We covered both overclocking technologies at length in previous videos, so any aspiring AMD overclocker should be familiar with both already.

PBO stands for Precision Boost Overdrive. It is an extension of the Precision Boost technology integrated in all AMD Ryzen CPUs. Precision Boost allows the CPU to opportunistically increase its clock frequency over base frequency based on the available power and thermal headroom.

Precision Boost Overdrive preserves all the automated intelligence and boost built into the Ryzen CPU. So, AMD claims it provides the user with the best of both worlds: on the one hand it provides the user with an ability to leverage superior cooling to achieve higher performance, and on the other hand the algorithm will still aim to maximize the performance in a wide variety of workloads.

Precision Boost Overdrive uses a proprietary algorithm with inputs from a plethora of sensors inside the CPU to determine what is the optimal frequency and voltage at any given time. It is important to mention that using Precision Boost Overdrive is a form of overclocking and is therefore not covered by warranty.

XMP is an Intel technology that lets you automatically overclock the system memory to improve system performance. XMP is an extension to the standard JEDEC specification that allows a memory vendor to program different settings onto the memory stick. The settings include the memory frequency, the memory timings as well as the memory voltage.

In our case the XMP rating of our memory is DDR4-4400. By enabling XMP we not only increase the memory frequency, but also change the infinity fabric to run in asynchronous mode.

By default, the infinity fabric, memory controller, and memory frequency operate in “synchronous mode.” That means the CPU will run all frequencies in 1 to 1 ratio. Synchronous mode is taxing for the CPU, so on most Ryzen CPUs, the system will automatically enable “Asynchronous mode” beyond a certain memory frequency. In asynchronous mode, the memory controller will operate at half the frequency of the system memory. The fabric clock will also run below system memory frequency. So, you will have a performance penalty. However, with enough memory speed you can overcome that performance penalty.

Most Ryzen 5000 CPUs will not run synchronous mode over DDR4-4000. Since our memory is rated at DDR4-4400, the system will automatically enable asynchronous mode.

Upon entering the BIOS

  • Press F2 to switch to Advanced Mode
  • Set Extreme Memory Profile(X.M.P.) to Profile1
  • Go to the Settings menu
  • Enter the AMD Overclocking submenu
    • Set Precision Boost Overdrive to Enabled

Then save and exit the BIOS.

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

  • SuperPI 4M: +2.86%
  • Geekbench 5 (single): +0.93%
  • Geekbench 5 (multi): +8.78%
  • HWBOT X265 4K: +6.38%
  • Cinebench R23 Single: +0.19%
  • Cinebench R23 Multi: +2.27%
  • V-Ray 5: +3.46%
  • 3DMark Night Raid: +4.23%
  • CS:GO FPS Bench: +0.54%
  • Final Fantasy XV: +2.84%
5900x pbo+xmp benchmark performance

We also check the 3DMark CPU profile improvement:

  • CPU Profile 1 Thread: +0.10%
  • CPU Profile 2 Threads: +0.21%
  • CPU Profile 4 Threads: +0.14%
  • CPU Profile 8 Threads: +0.18%
  • CPU Profile 16 Threads: +8.04%
  • CPU Profile Max Threads: +11.42%
5900x pbo + xmp 3dmark cpu profile performance

Enabling Precision Boost Overdrive allows the CPU to run at higher power consumption. So, we expect to see the largest performance gains in multithreaded applications. And that is in fact what we see with up to 8.78% benchmark performance increase and up to 11.42% increase in 3DMark CPU Profile.

When running Prime 95 Small FFTs with AVX enabled, the average effective CPU clock is 4162 MHz with 1.255 volts. The average CPU temperature is 90 degrees Celsius and the average CPU package power is 203 watts.

5900x pbo prime95 avx

When running Prime 95 Small FFTs with AVX disabled, the average effective CPU clock is 4223 MHz with 1.279 volts. The average CPU temperature is 85 degrees Celsius and the average CPU package power is 189 watts.

5900x pbo prime95 non-avx

Our second overclocking strategy covers two sub-strategies. We want to configure the CPU frequency manually but to judge stability we will use two approaches. Let us call them Strategy 2A and Strategy 2B

OC Strategy #2A: Ryzen 9 5900X Manual OC (P95 AVX)

The first approach is to check the stability in an ultimate worst-case scenario. For me, that’s Prime95 Small FFTs with AVX enabled. Generally speaking, passing this test means that your CPU will be able to withstand any workload, no matter how tough.

The second approach is to the check the stability in a more common scenario. For this video, this means passing Prime95 Small FFTs with AVX disabled as well as passing all the benchmarks we use to measure system performance.

We also tune the frequency for each CCD. CCD stands for Core Chiplet Die and is one of the chips on the AMD CPU. While a CCD used to consist of two CCXs paired together, on Zen 3 a CCD consists of a single CCX with 8 cores. While there is only 1 CPU Core voltage plane for a Ryzen 5000 CPU, so all CCDs run at the same voltage, each CCD can be configured with its own fine grain frequency. That means we can maximize the frequency for each CCD individually.

The difference between Strategy 2A and 2B is about 100 MHz for CCD0 and 150 MHz for CCD1.

For Strategy 2A, upon entering the BIOS

  • Press F2 to switch to Advanced Mode
  • Set CPU Ratio Mode to Per CCX
  • Set CCD0 CCX0 Ratio to 45.50
  • Set CCD1 CCX0 Ratio to 43.75
  • Set Extreme Memory Profile(X.M.P.) to Profile1
  • Set CPU Vcore to 1.325V

Then save and exit the BIOS.

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

  • SuperPI 4M: -3.78%
  • Geekbench 5 (single): -4.01%
  • Geekbench 5 (multi): +11.12%
  • HWBOT X265 4K: +9.31%
  • Cinebench R23 Single: -5.67%
  • Cinebench R23 Multi: 5.66%
  • V-Ray 5: +4.88%
  • 3DMark Night Raid: +4.88%
  • CS:GO FPS Bench: +1.87%
  • Final Fantasy XV: +3.82%

We also check the 3DMark CPU profile improvement:

  • CPU Profile 1 Thread: -5.02%
  • CPU Profile 2 Threads: -4.07%
  • CPU Profile 4 Threads: -1.65%
  • CPU Profile 8 Threads: +1.26%
  • CPU Profile 16 Threads: +8.68%
  • CPU Profile Max Threads: +13.70%

We see the biggest performance gains in multithreaded benchmark applications. Sadly, we also see significant performance losses in single and low-threaded benchmark applications. That is because at default the Precision Boost technology enables frequencies up to 4.8 GHz whereas our manual overclock is limited to 4.55 GHz.

When running Prime 95 Small FFTs with AVX enabled, the average effective CPU clock is 4463 MHz with 1.248 volts. The average CPU temperature is 93 degrees Celsius and the average CPU package power is 213 watts.

When running Prime 95 Small FFTs with AVX disabled, the average effective CPU clock is 4463 MHz with 1.260 volts. The average CPU temperature is 84 degrees Celsius and the average CPU package power is 188 watts.

OC Strategy #2B: Ryzen 9 5900X Manual OC (P95 non-AVX)

For Strategy 2B, upon entering the BIOS

  • Press F2 to switch to Advanced Mode
  • Set CPU Ratio Mode to Per CCX
  • Set CCD0 CCX0 Ratio to 46.50
  • Set CCD1 CCX0 Ratio to 45.25
  • Set Extreme Memory Profile(X.M.P.) to Profile1
  • Set CPU Vcore to 1.350V

Then save and exit the BIOS.

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

  • SuperPI 4M: -1.71%
  • Geekbench 5 (single): -1.97%
  • Geekbench 5 (multi): +12.64%
  • HWBOT X265 4K: +12.18%
  • Cinebench R23 Single: -3.80%
  • Cinebench R23 Multi: +9.47%
  • V-Ray 5: +9.51%
  • 3DMark Night Raid: +8.07%
  • CS:GO FPS Bench: +1.92%
  • Final Fantasy XV: +3.44%

We also check the 3DMark CPU profile improvement:

  • CPU Profile 1 Thread: -3.03%
  • CPU Profile 2 Threads: -1.96%
  • CPU Profile 4 Threads: +0.06%
  • CPU Profile 8 Threads: +3.80%
  • CPU Profile 16 Threads: +12.33%
  • CPU Profile Max Threads: +16.61%

We see the same result in Strategy 2B as we saw with Strategy 2A: significant performance gains in multi-threaded benchmark applications, but performance losses in low-threaded benchmarks.

When running Prime 95 Small FFTs with AVX enabled, the system does not pass the stability test even though it could run all our other benchmarks.

When running Prime 95 Small FFTs with AVX disabled, the average effective CPU clock is 4588 MHz with 1.284 volts. The average CPU temperature is 90 degrees Celsius and the average CPU package power is 203 watts.

OC Strategy #3: GIGABYTE Active OC Tuner

When I was first told about AOCT in the year 2021, I thought JagatReview had once again organized what is perhaps the greatest Amateur OverClocking Tournament in the world.

From 2012 until 2018, AOCT was the premier proving ground for up-and-coming Indonesian young overclocking talent. The JagatReview crew, home of the Indonesian overclocking legend Lucky_n00b, would travel across the country and host qualifiers at university campuses. Only new overclockers were eligible to enter. The winners would ultimately compete for the title of AOCT champion. In 2017, as AOCT champion BlueFiber even won a ticket to the HWBOT World Championship Qualifying event in Yogyakarta and made it to the Overclocking World Championship Final in Berlin later that year!

However, this is not that AOCT.

AOCT is short for Active OC Tuner and is GIGABYTE’s very clever way of solving one of AMD’s biggest problems when overclocking.

As we have already seen in the previous strategies: while Precision Boost Overdrive provides the best benchmark performance in single and low-threaded benchmark applications, the best multi-threaded performance is achieved by manually overclocking. So, you have to compromise best single threaded performance or best multi-threaded performance.

Active OC Tuner gives us the best of both worlds as it allows the system to actively switch between Precision Boost Overdrive and manual OC mode. AOCT requires little additional configuration work.

Think about AOCT as follows: it is exactly like Precision Boost Overdrive, but the lowest frequency is manually set by us. So, we need to know two things:

  1. What is the lowest frequency we will allow
  2. At which point do we want AOCT to switch between PBO and OC Mode

Sadly, we cannot simply configure a minimum frequency and have the system switch based on that. Instead, we need to use a proxy metric: a certain current threshold or a certain temperature threshold. There is not one specific method of determining the right threshold, so I’ll show you one example using Cinebench R23.

Okay, for our lowest frequency we choose our manual overclock from Strategy 2B which is an average frequency across all cores of 4587 MHz

In the Operating System, we first open HW Info. We make sure we can monitor both the Effective Clock Frequency and the Current (IOUT).

Then we start the Cinebench R23 multi-threaded benchmark workload and change the affinity to 1 core in task manager. Now monitor the effective clock frequency. It will be higher than our target of 4587 MHz. Now you can gradually increase the Cinebench R23 thread count. When you reach 4587 MHz or below, check the Current (IOUT) reading. This value will be our input for the AOCT CPU Current Limit.

In our case, we reach the frequency of 4587 MHz at 5 active threads. The current varies between 42 and 48 amps. To be on the safe side we pick 46A as the CPU Current Limit.

So, to reiterate what’s happening: AOCT will switch between OC mode and PBO when the CPU current hits 46A. Anything above 46A will engage manual OC mode; anything below 46A will engage Precision Boost Overdrive.

Now let’s configure the system

Upon entering the BIOS

  • Press F2 to switch to Advanced Mode
  • Set CPU Ratio Mode to Per CCX
  • Set CCD0 CCX0 Ratio to 46.50
  • Set CCD1 CCX0 Ratio to 45.25
  • Enter the Advanced CPU Settings submenu
    • Set Active OC Tuner to Enabled
    • Set CPU Current Limit to 46
    • Set CPU Temperature Limit to 100
  • Leave the Advanced CPU Settings submenu
  • Set Extreme Memory Profile(X.M.P.) to Profile1
  • Set CPU Vcore to 1.350V
  • Go to the Settings menu
  • Enter the AMD Overclocking submenu
    • Set Precision Boost Overdrive to Enabled

Then save and exit the BIOS.

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

  • SuperPI 4M: +3.33%
  • Geekbench 5 (single): +1.17%
  • Geekbench 5 (multi): +8.30%
  • HWBOT X265 4K: +12.34%
  • Cinebench R23 Single: +0.25%
  • Cinebench R23 Multi: +8.72%
  • V-Ray 5: +8.66%
  • 3DMark Night Raid: +6.47%
  • CS:GO FPS Bench: +2.24%
  • Final Fantasy XV: +4.17%

We also check the 3DMark CPU profile improvement:

  • CPU Profile 1 Thread: +0.10%
  • CPU Profile 2 Threads: +0.42%
  • CPU Profile 4 Threads: +0.80%
  • CPU Profile 8 Threads: +1.48%
  • CPU Profile 16 Threads: +12.88%
  • CPU Profile Max Threads: +15.45%

As we can see from the benchmark performance, we eliminated the performance loss in low-threaded benchmark applications by enabling PBO and maximized the performance gains in highly multi-threaded workloads by configuring our manual overclock. Active OC Tuner gives us the best of both worlds.

OC Strategy #4: Ryzen 9 5900X PBO Tuned

In our fourth overclocking strategy we return to Precision Boost Overdrive 2 and make use of the tools provided by AMD to further tune the algorithm.

We follow the PBO tuning process as outlined in SkatterBencher #24 with the Ryzen 7 5700G. As we have covered Precision Boost Overdrive 2 in detail in another article, I won’t put you through the same theory again.

Practically, we follow the same process. That means we choose a fixed CPU Vcore Loadline, manually increase the PBO power and current limits, increase the maximum CPU Boost Clock Override by 200 MHz, and use Curve Optimizer to tune each CPU core individually.

The result is that the PBO algorithm much more aggressively pursues higher voltages, which in turn provide us with higher overclocking frequencies.

The single threaded boost frequency goes up from 4950 MHz to 5125 MHz while the frequency under load for all-core non-avx increases from 4220 MHz to 4365 MHz.

Upon entering the BIOS

  • Press F2 to switch to Advanced Mode
  • Set Extreme Memory Profile(X.M.P.) to Profile1
  • Enter the CPU/VRM Settings submenu
    • Set CPU Vcore Loadline Calibration to Turbo
  • Leave the CPU/VRM Settings submenu
  • Go to the Settings menu
  • Enter the AMD Overclocking submenu
    • Set Precision Boost Overdrive to Advanced
    • Set PBO Limits to Manual
      • Set PPT Limit [W] to 250
      • Set TDC Limit [A] to 200
      • Set EDC Limit [A] to 200
    • Set Precision Boost Overdrive Scalar to Manual
    • Set Precision Boost Overdrive Scalar to 10X
    • Set Max CPU Boost Clock Override to 200MHz
    • Enter the Curve Optimizer submenu
      • Set Curve Optimizer to Per Core
      • Set Core 0 to Core 11 Curve Optimizer Sign to Negative
      • Set Core 0 to Core 11 Curve Optimizer Magnitude to 30, except Core 4
      • Set Core 4 Curve Optimizer Magnitude to 20

Then save and exit the BIOS.

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

  • SuperPI 4M: +6.47%
  • Geekbench 5 (single): +6.91%
  • Geekbench 5 (multi): +10.27%
  • HWBOT X265 4K: +8.42%
  • Cinebench R23 Single: +2.87%
  • Cinebench R23 Multi: +4.51%
  • V-Ray 5: +4.99%
  • 3DMark Night Raid: +6.28%
  • CS:GO FPS Bench: +0.69%
  • Final Fantasy XV: +3.17%

We also check the 3DMark CPU profile improvement:

  • CPU Profile 1 Thread: +2.61%
  • CPU Profile 2 Threads: +2.27%
  • CPU Profile 4 Threads: +1.02%
  • CPU Profile 8 Threads: +3.27%
  • CPU Profile 16 Threads: +9.72%
  • CPU Profile Max Threads: +13.05%

Our benchmark performance gains over stock settings range from +0.69% in CS:GO to +13.05% in 3DMark CPU Profile Max Threads. That’s a steady improvement from the +0.19% to +11.42% with standard PBO enabled.

When running Prime 95 Small FFTs with AVX enabled, the average effective CPU clock is 4279 MHz with 1.251 volts. The average CPU temperature is 90 degrees celsius and the average CPU package power is 207 watts.

When running Prime 95 Small FFTs with AVX disabled, the average effective CPU clock is 4365 MHz with 1.298 volts. The average CPU temperature is 88 degrees celsius and the average CPU package power is 201 watts.

OC Strategy #5: Ryzen 9 5900X PBO Supercharged

In our final overclocking strategy we are looking to supercharge the Precision Boost Overdrive algorithm to get even more performance.

In the next couple of paragraphs I will discuss where a supercharged PBO sits in the discussion of Ryzen CPU frequencies. I strongly recommend you sit back and go through this section with me as it should provide you a better understanding of what we’re trying to achieve in this last overclocking strategy. However, if you’re like “bro, just give me the settings” then feel free to skip ahead.

For those who are willing to stick with me, PBO supercharged sits at the very top of the Ryzen overclocking pyramid which starts at the CPU base frequency.

Base Frequency

Just like pretty much any other CPU on the market, the AMD Ryzen 9 5900X has a listed base frequency. This frequency is what AMD guarantees all cores of the CPU will run at, provided you have sufficient cooling and power delivery. For the Ryzen 9 5900X, this base frequency is 3.7 GHz.

Precision Boost

The Ryzen 9 5900X also comes with an AMD technology called Precision Boost 2. https://www.amd.com/en/support/kb/faq/cpu-pb2

Precision Boost allows the processor cores to run faster than the base frequency and thus improve the system performance. When enabled, the actual frequency is determined by a wide range of onboard sensors which analyze the system and processor health many times per second.

Precision Boost 2 employs a proprietary algorithm that brings together all the different inputs, then calculates what is the highest allowed voltage that can be set. Based on this voltage, the CPU then sets the frequency according to the voltage frequency curve of each of the processor cores. Note that the maximum target voltage of the algorithm is 1.5V, though maximum real voltage is subject to your motherboard’s VRM configuration.

While there’s no detailed information available on how the algorithm works exactly, what we do know is that generally speaking the more thermal, current, and power headroom there’s available, the higher your CPU will boost. For the Ryzen 9 5900X the listed maximum boost frequency is 4.8 GHz.

The key word in that last sentence is “listed”.

Because Precision Boost uses an algorithm with many input parameters to calculate a target frequency, rather than a fixed lookup table, the actual peak frequency cannot be controlled accurately. In the past this resulted in somewhat awkward situations where some CPUs wouldn’t actually hit the maximum advertised boost frequency.

For the Ryzen CPUs, there is actually three kinds of boost limits: the advertised maximum boost frequency, the firmware programmed maximum boost frequency, and the actual real world maximum boost frequency. Many media reported on the rather large discrepancy between these three frequencies when covering the Ryzen 5000 launch.

For Ryzen 5000 CPUs, the programmed maximum boost frequency is about 150 MHz higher than the advertised maximum boost frequency. For the Ryzen 3000 CPUs that was about 25 MHz or 50 MHz.

My interpretation is that by increasing the difference between the listed and programmed maximum boost frequency, hitting the listed boost frequency on Ryzen 5000 CPUs is much less an edge case of the algorithm than it was on Ryzen 3000 CPUs. Hence why we see more people getting higher than the listed boost on Ryzen 5000 CPUs as opposed to lower than listed boost on Ryzen 3000 CPUs. But that’s just speculation on my behalf.

Either way, what’s important to understand is that actual frequency is the result of a dynamic algorithm rather than a fixed ruleset.

At stock, on my CPU the maximum boost frequency ranges from 4750 MHz on cores 3, 8 and 9, to 4950 MHz on cores 1 and 4.

But that’s still not all …

Effective Clock

The next important thing to understand is that there’s a big difference between the “Core Frequency” and the “Effective Clock”. Everything I’ve discussed up to this point relates to the Core Frequency.

Core Frequency is the frequency that is configured by the CPU and read by software tools from the CPU registers. It is the frequency that you’ll see reported in CPU-Z for example. Effective Clock measures the average actual clock cycles across a polling interval.

The difference between the two values is that the Core Frequency is the frequency as measured at a specific moment in time, whereas the Effective Clock measures the total clock cycles between two moments in time.

These two measurements can differ a lot because modern CPUs like the Ryzen 5000 have very advanced power saving features. When a CPU core has nothing to execute it will quickly go to a low power state. This is great as it opens up more power budget for any of the other cores that do need to execute. So those other cores may boost to a higher frequency. I had a closer look at the behavior of the Core Clock and Effective Clock in my Ryzen 5 5600X overclocking video, so check it out if you want more information.

Another area where the effective clock is particularly relevant is Clock Stretching.

Clock Stretching is a safety feature that is built into all AMD Ryzen CPUs. When the CPU figures the actual voltage is too low to sustain a stable system at a given frequency, it will reduce the clock period until the voltage is back at the acceptable level. Effectively, the CPU suspends the execution of tasks until stability is regained.

The result of clock stretching is that while the system will report the Core Clock as normal, the Effective Clock will be lower because there are fewer amount of clock cycles. Obviously, the performance will also be lower.

Clock Stretching has been a major topic among AMD Ryzen enthusiasts. Typically, users would find that setting a higher frequency would result in lower performance. The best way to check if clock stretching is happening is by checking the Effective Clock measurement in HWinfo. If the effective clock is significantly lower than the configured core frequency when the system is under load, then it is likely that clock stretching is happening on your system.

For users like you and I, what matters most is the effective clock as this relates directly to the compute performance of your system. So, while it’s nice to talk about base clocks, listed max boost clocks, programmed max boost clocks, or actual max boost clocks … none of those matter unless it means the effective clock is also higher.

At stock, on my CPU the maximum effective clock frequency ranges from 4567 MHz on core 11 to 4852 MHz on Core 1.

Precision Boost Overdrive 2

Along with the Precision Boost technology, AMD also developed a Precision Boost Overdrive technology designed for overclockers.

Precision Boost Overdrive preserves all the automated intelligence and boost that comes with the Precision Boost algorithm. However, it provides overclockers with some additional tools and options to manipulate the algorithm so it would boost higher in both single threaded and multi-threaded workload situations. There are six tools to highlight:

  1. Package Power Tracking or PPT, measured in watts, is the amount of power the processor can draw from the socket before the boost levels off. It is important to note that this measure includes the power from all parts of the CPU, including the cores but also the memory controller and integrated graphics.
  • Electrical Design Current or EDC, measured in amps, is the peak current that the motherboard VRM can supply under transient conditions. A higher spec (and more expensive) VRM will provide more headroom.
  • Thermal Design Current or TDC, measured in amps, is the current the VRM can supply for a sustained period of time. Essentially, the limiting factor for this will be the combination of the VRM components and the VRM thermal solution.
  • Scalar, expressed as a factor, is a way to tell the boost algorithm that the CPU quality is better than it actually is. A higher-quality CPU can reach higher frequencies at the same voltage or use higher voltages within the same thermal constraints. Effectively, the scalar can fool the PBO algorithm in pushing more voltage to the CPU even if it would normally not do so given the factory-fused silicon quality indicator.
  • Boost Override or Fmax Offset, measured in MHz, is a tool to set a higher ceiling for the maximum CPU frequency. The Fmax Offset can be set in steps of 25 MHz up to 200 MHz.
  • Curve Optimizer is a tool that enables adaptive undervolting allowing for additional voltage and thermal headroom, resulting in higher frequencies and longer boost duration.

I explored the ins and outs of Precision Boost Overdrive 2 in my Ryzen 7 5700G SkatterBencher article, so if you want to learn more about the impact of each of these settings I suggest you to check out that video.

When enabling PBO on my CPU, the maximum boost frequency ranges from 4626 MHz on cores 0 to 4901 MHz on cores 1 and 4. The effective clock ranges from 4568 MHz on Core 10 to 4817 MHz on Core 1.

When enabling Precision Boost Overdrive in the BIOS, typically you’ll get values that are suggested by AMD or which are programmed by the motherboard vendor. However, you can also override those settings and manually tune each to your liking. We went through the manual tuning process in our previous overclocking strategy.

What’s crucial to understand when tuning the Precision Boost algorithm with the tools provided by Precision Boost Overdrive is that you’re still working within the restrictive parameters set by the algorithm. That means: a maximum long-term temperature of 90 degrees Celsius, a maximum boost frequency equal to the default programmed maximum boost frequency plus 200 MHz, and a maximum CPU core voltage of 1.5V.

When manually tuning PBO on my CPU, the maximum boost frequency ranges from 4600 MHz on cores 0 to 5125 MHz on core 1. The effective clock ranges from 4737 MHz on Core 8 to 4991 MHz on Core 1.

When you’ve exhausted all options of Precision Boost Overdrive, that’s when we aim to supercharge PBO.

PBO Supercharged

If you’ve come this far in the article, congratulations.

To best explain what it means to supercharge PBO, let’s look at the V/f curves again.

The voltage frequency curve, or V/f curve, is a line that describes the relationship between the operating frequency and the voltage required to run stably at that frequency. Each individual core in your AMD Ryzen CPU has a V/f curve. Better cores which require less voltage for a given frequency will be able to boost to higher frequencies given a certain voltage.

Precision Boost technology and its extension Precision Boost Overdrive use this V/f curve information to dynamically increase the CPU operating frequency. The boost algorithm determines the maximum allowed voltage for a given set of input parameters. The inputs include not just power, current, and temperature, but also quanity of active cores, the core quality, the V/f curves, and so on. Once the algorithm has determined the maximum allowed voltage, it applies the according frequency based on the V/f curve.

Let’s take a simplified example assuming all cores have the same V/f curve and we’re using a single threaded benchmark application.

If the load is very light, the maximum allowed voltage might be 1.35V in which case the frequency will be the associated 4775 MHz. If the load is very heavy, then the maximum allowed voltage might only be 1.2V and then the associated frequency is 4500 MHz.

When enabling Precision Boost Overdrive, we give additional headroom to certain parameters like power and current. However, other parameters like maximum temperature of 90 degrees Celsius and maximum voltage of 1.5V are fixed and cannot be changed. The impact of this additional headroom can be seen most evidently in high-power or high-current heavy multithreaded workloads.

One of the most powerful tools included in Precision Boost Overdrive is the Curve Optimizer. Curve Optimizer allows us to adjust the V/f curve for each individual core positively or negatively up to 30 steps of 3 to 5 mV. So maximum -150mV or +150mV.

Returning to our example, if our CPU is really good and we can offset the entire curve by negative 30 steps, the voltage required for a given frequency is much lower. So, if we have a heavy workload and the maximum allowed voltage is 1.2V, the associated frequency is now 4775 MHz instead of 4600 MHz. However, our maximum frequency is still limited to 4850 MHz which will be run at 1.25V instead of 1.40V.

To solve this frequency ceiling we can use another PBO tool called Maximum Boost Override. AMD allows for up to 200 MHz higher frequency ceiling than default. In our case, that would open up the frequency to 5050 MHz with a voltage of 1.45V.

Up to this point, we’re just using the available PBO tools. However, you can see that there’s still room for improvement. For one, we are not hitting the ceiling of the maximum voltage yet. Two, we are hitting the ceiling of the CPU frequency. Maybe our CPU could run even faster if only we’d allow for more voltage.

That’s where PBO supercharged comes into action.

While the Precision Boost algorithm is incredibly smart, there are still ways to outsmart it as a user. There are two important options that will help us in particular: BCLK and voltage offsets.

The base clock frequency is the reference clock frequency for many parts in your system, including the CPU cores but also the system memory, PCIe, and SATA. When increasing the base clock frequency you change all the frequencies that use the BCLK as reference clock. While this can result in additional performance, it can also cause instability so be careful.

For example, on this platform, I must use an M.2 drive connected to CPU PCIe lanes to use over 100.5 MHz base clock frequency as my SATA drives are no longer showing up.

When increasing the BCLK from 100 MHz to 103 MHz, the frequency associated with a given voltage will increase by the same amount. So, at 1.20V we’re now getting 4918 MHz. Or, at 1.45V we’re now getting 5200 MHz. This is of course a nice frequency bump but without additional voltage this won’t be stable

By adding an additional voltage offset we can look for stability at the highest frequency range. But, also keep in mind that adding an offset to the entire V/f curve means that you’ll also get higher voltage at lower frequencies. In heavy multi-threaded workloads that means you’ll run out of thermal headroom faster than without the voltage offset.

In our example V/f curve, we started out with 1.2V giving 4500 MHz, and a maximum frequency of 4850 MHz at 1.45V. After “supercharging” PBO, our 1.2V now gives us 4841 MHz and our maximum frequency is 5253 MHz at 1.55V.

Now that we have all the information how to supercharge PBO, let’s get into the BIOS and configure our overclock.

Upon entering the BIOS

  • Press F2 to switch to Advanced Mode
  • Set CPU Clock Control to 102.90MHz
  • Set Extreme Memory Profile(X.M.P.) to Profile1
  • Set CPU Vcore to Normal
  • Set Dynamic Vcore(DVID) to 0.05V
  • Enter the CPU/VRM Settings submenu
    • Set CPU Vcore Loadline Calibration to Turbo
  • Leave the CPU/VRM Settings submenu
  • Go to the Settings menu
  • Enter the AMD Overclocking submenu
    • Set Precision Boost Overdrive to Advanced
    • Set PBO Limits to Manual
      • Set PPT Limit [W] to 250
      • Set TDC Limit [A] to 200
      • Set EDC Limit [A] to 200
    • Set Precision Boost Overdrive Scalar to Manual
    • Set Precision Boost Overdrive Scalar to 10X
    • Set Max CPU Boost Clock Override to 200MHz
    • Enter the Curve Optimizer submenu
      • Set Curve Optimizer to Per Core
      • Set Core 0 to Core 11 Curve Optimizer Sign to Negative
      • Set Core 0 and Core 7 Curve Optimizer Magnitude to 20
      • Set Core 1 Curve Optimizer Magnitude to 10
      • Set Core 2, Core 6, Core 8, and Core 9 Curve Optimizer Magnitude to 25
      • Set Core 3, Core 5, Core 10, and Core 11 Curve Optimizer Magnitude to 30
      • Set Core 4 Curve Optimizer Magnitude to 1

Then save and exit the BIOS.

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

  • SuperPI 4M: +6.75%
  • Geekbench 5 (single): +8.76%
  • Geekbench 5 (multi): +14.07%
  • HWBOT X265 4K: +12.37%
  • Cinebench R23 Single: +3.43%
  • Cinebench R23 Multi: +8.72%
  • V-Ray 5: +7.83%
  • 3DMark Night Raid: +10.32%
  • CS:GO FPS Bench: +1.24%
  • Final Fantasy XV: +5.23%

We also check the 3DMark CPU profile improvement:

  • CPU Profile 1 Thread: +3.76%
  • CPU Profile 2 Threads: +3.07%
  • CPU Profile 4 Threads: +4.08%
  • CPU Profile 8 Threads: +5.72%
  • CPU Profile 16 Threads: +13.88%
  • CPU Profile Max Threads: +17.17%

We see the best benchmark performance across all applications. This is of course thanks to the increase CPU frequencies, but also in part thanks to a higher infinity fabric and memory clock frequency which are affected by the BCLK increase..

When running Prime 95 Small FFTs with AVX enabled, the average effective CPU clock is 4158 MHz with 1.244 volts. The average CPU temperature is 90 degrees celsius and the average CPU package power is 208 watts.

When running Prime 95 Small FFTs with AVX disabled, the average effective CPU clock is 4321 MHz with 1.302 volts. The average CPU temperature is 90 degrees celsius and the average CPU package power is 209 watts.

Before we wrap up this video, let’s have a closer look at the supercharged PBO results as there’s a couple of things I want to highlight.

Overall, compared to PBO tuned, PBO supercharged gives us the better performance in all benchmarks. That’s pretty good. However, in Prime 95 non-AVX and Prime 95 AVX the average effective clock frequency is lower: 4321 and 4158 MHz versus 4365 and 4279 MHz. That’s most likely due to the fact that the adding a fixed voltage offset to the V/f curve may yield a lower frequency at a certain point on the V/f curve.

Returning to our previous example, you can see that at 0.9V the frequency with BCLK and voltage offset is 3914 MHz and without 4000 MHz. So while you might get more top end speed, in thermal or power limited scenarios you may get a lower frequency.

The highest Core Clock reported in the operating system is 5223 MHz for Core 1. This is approximately 3% higher than the programmed 1T boost frequency of 4950 MHz with an 200MHz boost override. So it falls in line with our expectations after a BCLK overclock. The average maximum core clock across all 12 cores also increased from 4837 MHz to 5083 MHz. In other words: every single core of this Ryzen 9 5900X now boosts to over 5 GHz.

However, when using the Corecycler application to check the effective clock frequency in a single threaded workload we find that the maximum effective clock is pretty much the same: 5050 MHz for Core 1. Then again, the average effective clock in single threaded application across all cores did increase from 4828 MHz to 4910 MHz.

The single threaded performance increase from supercharging PBO really depends on the benchmark application and the strength of the core. To illustrate this I use the really light benchmark application SuperPI 16M and track the effective clock frequency across 1 benchmark run for two cores: the strong Core 1 and the weak Core 9.

  • At stock, the average effective clock frequency is 4890 MHz for Core 1 and 4675 MHz for Core 9.
  • With PBO enabled, the average effective clock frequency is 4863 MHz for Core 1 and 4645 MHz for Core 9.
  • With PBO tuned, the average effective clock frequency is 5030 MHz for Core 1 and 4804 MHz for Core 9.
  • At PBO supercharged, the average effective clock frequency is 5053 MHz for Core 1 and 4967 MHz for Core 9.

It’s clear that while Core 9 is definitely weaker than Core 1, it benefits more from supercharging the Precision Boost algorithm.

AMD Ryzen 9 5900X X570S Conclusion

Alright, let us wrap this up. My original plan with this Ryzen 9 5900X system was two-fold.

  1. First, I wanted to explore the GIGABYTE Active OC Tuner feature and see how I could put it to use for achieving higher performance.
  2. Second, I wanted to revisit overclocking with Precision Boost Overdrive 2 as Curve Optimizer wasn’t quite ready when I tested the CPUs leading up to the launch last November.

The GIGABYTE Active OC Tuner is a neat little feature that allows the user to easily work around the main limitation of manually overclocking Ryzen CPUs. That is: when manually overclocking you have to sacrifice a lot of single threaded performance in order to obtain much higher multi-threaded performance. A properly configured Active OC Tuner will switch between Precision Boost Overdrive and manual OC mode right at the point where the PBO algorithm would set a CPU frequency lower than your manual overclock. This ensures you enjoy both the peak single threaded performance offered by Precision Boost and the peak multithreaded performance offered by your manual overclock. That’s a clear win-win in my book.

Playing around with Precision Boost Overdrive 2 and its main feature Curve Optimizer was also a lot of fun. I went through the basics before with the Ryzen 5 5700G and applying what I learned then, resulted in further improved performance today.

Supercharging Precision Boost Overdrive by employing BCLK overclocking and adding an additional voltage offset was certainly an interesting journey. The overall performance increased across the board, so the effort certainly paid off. That said, there are still elements limiting the final performance.

  1. One, it is a bit annoying that you need an NVMe drive to use BCLK as my SATA drive was not detected above 100.5 MHz BCLK or so.
  2. Two, the maximum CPU temperature for sustained loads is 90 degrees Celsius and there’s no way to override this limit. This limits the performance in all PBO situations. The added voltage when supercharging PBO results in ultimately a lower sustained frequency in heavy multi-threaded workloads as more voltage makes us hit the maximum temperature quicker.
  3. Three, while for the best CPU core I could see a maximum Core Clock of 5223 MHz, the maximum effective clock when supercharged was pretty much the same as with regular PBO tuning. However, for the weaker cores I definitely saw higher effective clocks when supercharging PBO.

Maybe the most important takeaway from this overclocking guide is that there’s always a way to extract more performance out of your system. For example, it is possible to use Active OC Tuner in combination with a Supercharged Precision Boost Overdrive. But, I’ll leave that for others to try out.

Thanks for reading! As per usual if you have any questions or comments, feel free to drop them in the comment section below. ‘Till the next time.

2 thoughts on “SkatterBencher #26: AMD Ryzen 9 5900X Overclocked to 5223 MHz

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    […] went through the process of explaining what I mean by supercharging PBO in two previous articles: SkatterBencher #26 with the Ryzen 9 5900X and SkatterBencher #27 with the Ryzen 9 5950X. It’s quite a lengthy and detailed overview so I […]

  2. SkatterBencher #27: AMD Ryzen 9 5950X Overclocked to 5117 MHz | SkatterBencher

    […] went through the process of explaining what I mean by supercharging PBO in my previous SkatterBencher article with the Ryzen 9 5900X. The whole explanation took quite some time so I’ll try to keep it short […]

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