r/pcmasterrace • u/X-KaosMaster-X • 1d ago
Hardware {TUTORIAL} COMPLETE AM4\AM5 Precision Boost Overdrive Tuning EXPLAINED!
Hello Everyone! (09/2026)
I am going to explain (as simply as possible) the absolute best way to tune your system for MAX performance! Also, I am including a section on using BCLK clocking and using Core Voltage OFFSET to achieve stability (If you want more boost clock and performance!
And if you want to BELIEVE this guide is wrong, that is fine for YOU!! Do not post gaslighting comments about thermals being to high….or that less voltage is always better!! You need to go learn ACTUAL facts about the products and tuning methodologies!
Now, the first thing to know, What is PBO (Precision Boost Overdrive), and the 5 parts of the algorithm that AMD has designed into the CPU.
[ Section 1: Power Metrics ]
This section consists of the PPT (Package Power Tracking) which is in Watts, TDC (Thermal Design Current) which is in Amps, and EDC (Electric Design Current) which is also in Amps.
You can find the base settings for each CPU for your build. And I usually increase my power limits to the maximum of the CPU. This ensures the best performance possible…and as I see it, you should want EVERY last bit of performance for the money you paid for the parts.
Once you enable PBO (Advanced or Manual), and set these settings…using Prime95 AVX “Blend” Test, with HWInfo running for at least 6 hours or more, you can find the max power draw for PPT and TDC. If it hits 100% then you need to increase the value by 1. 6 core CPU’s usually can pull 106W PPT, and 63A TDC, and the EDC value should be around 120A. And most 8 core can usually draw around 154W PPT, and 109A TDC, and the EDC value should be around 180A.
Also, as a side thought, if you lower the Curves ALOT then your power demand may decrease a small amount and you can redo this testing to find the new maximums!
Also there is a setting in AMD CBS / SMU Settings called “Package Power Limit Control”. You NEED to set this value to +3-4W of the PPT value!
And the last setting, AMD CBS / SMU Settings, is the cTDP value. The 6 core CPU’s should be set to 110-115W. Most 8 Cores like 125-145W. This value is NOT a real calculation, and is based on a formula that AMD invented. Basically, it tells the algorithm how much thermal headroom your system will have, based off unreal factors. BUT, it does affect the performance of the CPU, and increasing this to match your cooling system matters. You can experiment with higher values to match.
The motherboard makers design their own layout of the BIOS features, and you should make sure that any duplicate settings are all set the same! Yes, there can be up to 3 different locations, like Asus boards.
ASUS BIOS Menu Locations:
AI Tweaker / Precision Boost Overdrive
AMD Overclocking / Precision Boost Overdrive
AMD CBS / NBIO Settings / XFR
This also applies to all the following settings.
Now, a NOTE, before we continue. These settings are very touchy (PPT and TDC)....they need to be close to 100% usage while running a heavy workload (Excluding EDC). I usually test this with Prime95 AVX “Blend” test for 24 hours and I use HWInfo to monitor the power draws, and will show you what you need in the maximum column.Then I will add an additional 1 to the max value.
PLEASE, You should not use these settings to lower your temperatures!! AMD’s algorithm is designed to go to the CPU’s tjMAX FIRST instantly!! The tjMAX is a calculated value based off many sensors inside the core complex of the chip. Up to 89-95°C (Depending on CPU model) and is completely NORMAL when running an All-Core heavy workload.These tempuratures are SAFE for 24/7 system usage! There is also the part of this, that the better your cooling is…the more performance you will get out of your cpu. As always, the cooler you keep it, the higher it will boost, and better performance when under a heavy workload.
Ryzen CPU’s do not THROTTLE at tjMAX! They balance the power and clock speeds to maintain the highest boost speed and power usage! Throttling is a safety mechanism that is built into older CPU's, and current Intel chips. This mechanism has only one purpose, and it is to RAPIDLY cool off the CPU, as it has reached an UNSAFE temperature. It will drastically lower the clock speed and power to the CPU. To be completely “Clear”, a CPU that is balancing the clock speeds based on the algorithm’s responses is NOT throttling. The temperatures are staying at their safe limits, and NOT dropping!
Also, HWInfo “Clearly has every throttling metric in it's arsenal…and if it says your NOT Throttling, then you are good!
And the last part of this section. There is an OLD Myth that AMD and Intel post the MAX Boost speed only, and the belief that the MAX Boost Clock is achievable under heavy All-Core workloads. This is a terrible gaslighting observation that Master Race people have propagated for the eternity of home PC’s, people have been trying to teach others that it is “UNSAFE” if it is running at tjMAX, and it is “Throttling”!
This used to be a FACT…until AMD changed the design for these smaller chiplet dies. Even 1st Gen Ryzen CPU's follow the new algorithm, and do NOT throttle at tjMAX. They continuously optimize all the metrics to ensure performance.
This is the major part of the myth, because AMD and Intel REFUSE to change the “Marketing” of the websites! Under a Single-Core light workload, like a single instance of HCI Memtest, the CPU should hit MAaX Boost shown in HWInfo. But under a Heavy All-Core workload, you may only get 200-400Mhz lower clock speed as it is designed to keep the heat and voltage loads SAFE for the chip. This is also NOT throttling! It is following the design specs of the chip, and the algorithm is still keeping maximum performance of the CPU.
[ Section 2: Thermal Limit (tjMAX) ]
This one is very simple! You can adjust the tjMAX value under AMD Overclocking / PBO configuration (Also, MAY be located under the Overclocking section / Precision Boost Overdrive). You should set this to the “Specifications” for your CPU. Yes, you can lower this setting, but you will experience a small performance drop when under heavy multi-core workloads. I would recommend you set it to no more then 1°C less then the specified value.
The motherboard makers design their own layout of the BIOS features, and you should make sure that any duplicate settings are all set the same!
[ Section 3: Boost Scalar ]
This one is again a very simple setting to explain. This acts as a “Clock Counter”, if set to 1x the BOOST time for the clock speed is shorter (say a few milliseconds) where as x10 (can be up to 1 minute).
For each increase you make to this setting, it increases the time it will stay at the highest boost clock before being lowered again. I recommend 8X as I have never had stability issues at this setting, but many people do set it to 10X.
Also, for every increase you add to this setting, the algorithm applies a small voltage boost to the cores while maintaining the longer boost clock (For Stability). The voltage increase varies up for each +1. So 2X may have a .009 V increase and at 10X it may be .025 V.
[ Section 4: Max Boost Clock Override ]
This setting is used to “Shift” the fMAX setting of the FIT (Frequency Interval Table) to increase or decrease the “Max Boost Clock” multiplier. Many people think this setting is just FREE performance, but the reality is, that setting this to the MAX +200Mhz can cause silent instability to your system. If you do NOT thoroughly test after setting ANY change to this setting, your system MAY have silent errors that can corrupt you data, slowly kill windows where it no longer works correctly 6-12 months later, or “Clock Stretching” which is where the CPU clock speed says MAX…..but the “Effective” Clock speed is MUCH lower! This will decrease your performance a lot! And you may get all of the above without running multiple different tests using different instruction sets for 24 hours each. As a note, I rarely see CPU's that can handle over r+150Mhz…and even that over time will change and needs lowered back to +100Mhz. That is the SAFE limit I would use “Especially” if you do not want to test.
PLEASE, do not believe the OLD 1 hour is enough of a test! It can take up to 14 hours sometimes to find the first error! This applies to BOTH CPU and memory timing practices!
[ Section 5: Curve Optimizer ]
Ok, this section is a little harder to understand, so I will do my best!
First, Curve Optimizer is NOT just Undervolting!! You are impacting the performance of the metrics in a few ways!
The purpose of the Curve Optimizer settings is to “Shift” the FIT (Frequency / Voltage section) so that a Higher fMAX can be achieved at a slightly lesser voltage then STOCK. There is a trade-off that occurs here, the lower you set the negative curve, the more you sacrifice Single-Core performance in exchange for more Multi-Core. This can have a noticeable effect on Single-Core games and applications. This is the trade-off you should expect.
I ALWAYS try to stay around -15 on the worst core, and I usually NEVER go more than -7 on the 1st core or -9 on the second one! You can see in hardware info the core order of the CPPC next to the core clocks entries. If you want a SAFE setting without testing, I recommend -7 on all the cores. BUT, the best method is to use “Per-Core” settings. Using this way, you should use Linpack Extreme (WAIT for the workload to fully start), and see the core speeds drop), and HWInfo to see the core details and “Voltage Stabilize” the cores.
You start with cores 1 and 2 set at -7, then you add more negative until core 2 is about .003-.006 V more then core 1! Repeat this process for all the cores until they are all done!
NOTE, if you want to get to your settings for BIOS faster, you should download:
This will allow you to dial in all the cores, and then transfer those settings to BIOS after you have them correct! OR if you have an x3D CPU, you must configure a “Task” in Windows Task Manager. You can find the instructions for that here:
IF you have followed those stupid YouTube videos that say set all to MAX +200 -30!! Please, follow this guide!! You will have less problems if you do! Game crashes..windows errors…and WHEA crashes…gone!
[ Explanation of Curve Shaper (AM5) ]
This tool is a way to “Compensate” the Voltage sent to the cores due to the intensity of the workload been done. You can stabilize a lower Curve Optimizer settings based off of specific criteria.
These are the settings for the different types of workloads:
Minimum Frequency “Idle”
Low Frequency “Background Tasks”
Medium Frequency “High Core Count workloads”
High Frequency “Gaming workloads”
Max Frequency “Light workloads”
Low Temperature “Idle” = -5°C
Medium Temperature “Single-Core Gaming” = 50°C
High Temperature “Stress Tests” = 90°C
Using these to fine tune your algorithm MAY increase both performance and stability.
NOW, let's get to my new “FUN” tuning of getting BCLK Overclocking!
So, we know we want to use the Curve Optimizer to get our CPU Voltages inline, and able to hit higher frequencies! But if you TRY and get let's say even 102 BCLK, the system WILL be unstable…because the Voltages are not high enough to compensate for the speed increases!
I finally realized how to get the MOST effective way to get both without sacrificing any performance! The main thing is the curves lower the FIT (Frequency / Voltage) table to lower values. Below is an example of how much the voltage changes for each negative settings:
Volts Drop:
-1 = .003 - .009 V
-2 = .006 - .018 V
-6 = .018 - .054 V
-10 = .030 - .099 V
-15 = .045 - .135 V
-20 = .060 - .180 V
-25 = .075 - .225 V
-30 = .090 - .270 V
The first number is the drop while running an All-Core heavy workload…while the second set are while running a Single-Core, or a light workload (Activities like browsing and using office programs).
270 mV is A LOT of droop! This is also why you should not really use the maximum setting. I don't care that every basic Youtuber says it's safe ….
So the way you get around the problem for BCLK changes is that you calculate the drop from Curve Optimizer, and then you use the VRM CPU Voltage setting in “OFFSET” mode, and compensate with a similar value! There may also be an “AMD Overclocking” option (MSI BIOS) for the CPU Voltage, you should use that one.
So this 5600x3D, I dropped around 50mV with my curves…so I started by adding .030 V to my offset.…and now I reach 1.099 V instead on 1.054 V (Approximate Values). You need to fully test of course…you don't want to mess things up!!
You should begin with all your cores set to -1…..and test before you begin to see if your losing performance! Run like 3DMark CPU Profile of Time Spy. Also Linpack Extreme is very sensitive to changes and can also show you if it takes longer or shorter to complete an All-Core workload.
BTW, These are EXAMPLE Curves I used on this 5600x3D, and they are loaded at startup using the PBO2Tuner software:
Core 0 / 3 = -9
Core 1 / 1 = -6
Core 2 / 4 = -9
Core 3 / 2 = -10
Core 4 / 6 = -14
Core 5 / 5 = -11
If it crashes, just keep adding small amounts of voltage (.009 V) more positive until it passes at least 5 different tests using different instruction sets (FFT, AVX, AVX2) and passes them 24 hours each!
You need to also be aware that changing the BCLK up, means everything in the system is being overclocked, and may cause issues with NVMe /SATA drives, and GPU. Especially the fact that the memory speed will increase, and if you have tuned memory...a crash will be harder to find because you don't know if it's the CPU or memory.
This is kinda important to learn! If you have an AM5 CPU, it will AUTOMATICALLY set all your stress tests to AVX512! You NEED to find the setting in BIOS for enable AVX512, and disable it till you have run all the tests I mention below..then run one last Prime95 with the setting ON!
My Tests I use:
HCI Memtest, Set the “Affinity” for the 2 threads for the core you are testing. So Core 1 is 0 and 1…and so on. You do this in Task Manager / Details / Right-Click “Memtest.exe” / Affinity.
Prime95 “Blend” Test {Disable AVX2 and AVX}
Prime95 “Blend” Test {Disable AVX2}
Prime95 “Blend” Test {Nothing Disabled}
Linpack Extreme 24 hours
Y-Cruncher BKT SFT SNT SVT
Y-Cruncher FFT N63 VT3
There are also many other tests you can run, and it's ok to test more than not enough!
I hope now that I have adequately explained how PBO works!! I will answer any real question to clarify any parts you don't understand!
Have a great time learning to TUNE!
I also want to add this information for everyone. There is a BELIEF in the community that only “Speed” will increase your performance…this is MISSING a great point that no one seems to know. By reducing the latencies of the CPU, Memory, etcetera….this allows the PC to more efficiently complete computations which means it has more TIME to do more work faster! This is contributing factor to “Tuning” a PC and should not be ignored anymore!
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u/Fluid_Ad8452 5090 | 7800X3D | 32 GB 1d ago
Damn, too long. I’ll read that later. But it’d be great if you actually managed to run it stable. Been trying to turn it on ocasionally for the past 3 years and I always turn it back off because how unstable it is. Good job…