Overclock.net - An Overclocking Community - View Single Post - Undervolting/Editing P-States For Piledriver using AMD MrsTweaker (Mini Guide)

View Single Post
post #1 of (permalink) Old 07-02-2014, 12:36 PM - Thread Starter
New to Overclock.net
Undervolter's Avatar
Join Date: Mar 2013
Posts: 4,580
Rep: 520 (Unique: 256)
I stumbled upon this wonderful utility, an equivalent of K10Stat (which was for K10 architecture) and since i couldn't find an easily understandable guide and googled for long to solve all my problems, i decided to make a quick, hopefully easy to comprehend guide. This guide works for Win7 x64. It probably works for Win8 too. If it doesn't, too bad, you wanted tiles... biggrin.gif

The guide should work for NON overclocked configurations. So BIOS values must be at defaults. it MAY or MAY NOT work for overclocked configurations (not tested).

Utilities needed:

PSCheck 3.4.1 (AMD's tool):


or http://s000.tinyupload.com/index.php?file_id=35414757528187612550

AMD MsrTweaker 1.1 (it's CLI, no GUI)

http://www.brightsideofnews.com/2013/04/09/amdmsrtweaker-v11-released2c-trinity-support-inside/ (author's site).

1) Install PSCheck.
2) Unzip AMDMsrTweaker to a folder with the name "AmdMsrTweaker" (preferably, you can use other name, but this is a convention name that will go on for this post). For 64 bit Windows, put the contents of x64 folder in the "AmdMsrTweaker" folder (delete the empty x64 folder).

3) Run the executable of AMDMsrTweaker and take a screenshot of it, save it. These are the default values, you 'd better keep them in case something goes wrong and as guidelines.

Example, this is default from my FX-6300 (except for P2 which i had already undervolted in BIOS):

4) Position the folder "AmdMsrTweaker" in C:

5) Create on your desktop an empty .txt file. Rename it as "AMDMsrTweaker". Open it. You need to input the P-States and voltages that you want to change. Those that you don't want to change, you can leave aside. You can also disable APM or Turbo, using 0 or 1, but it's better to keep things simple and leave that part to the BIOS. Inside the txt you must write as example:

C:\AmdMsrTweaker\AmdMsrTweaker.exe [email protected] [email protected] [email protected] [email protected]

The first part (up to .exe) is the path of your executable. Then you input the desired [email protected] voltage. In my case, i wanted to change only 4 P-states. The above settings are IBT-AVX stable for my FX6300, but each motherboard and chip is different. They aren't fully optimized, they can probably go lower, but it was a quick run i did last night and i like round numbers. Ideally you 'd want to stress test each P-State with Prime95, but since i was in a haste, i went away with IBT AVX. Besides, since these are intermediate P-States, they don't get too much stressed in real life before going to the highest P-State (that i didn't change here, since i have it undervolted through BIOS - see P2 in the previous screenshot). For someone who wants to undervolt the highest P-State, he must also input P2 values. P1 and P0 are turbo values, if you have turbo disabled in BIOS, they shouldn't concern you at all. In my case, i have turbo disabled in BIOS. However, one could edit these states too and undervolt them as well. There is though, ONE difference. If someone wants to edit and use the turbo-states, there are some conditions:

- APM MUST be enabled.
- The highest turbo value in BIOS must be the same as the one edited in the batch file.
- The voltage set in BIOS as manual, must be the same value that the highest turbo state needs to use.

In my tested configuration for example, the full string for turbo enabled, but reduced to 4Ghz, is:

C:\AmdMsrTweaker\AmdMsrTweaker.exe [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected]

So in BIOS, i have: APM enabled, Turbo set manually to 4Ghz (multi 20), manual vcore 1.2875v. A bad conseguence though of having to enable APM, is that in very high stress, as in Prime95, your CPU at stock, will be mini-throttling. This is because Prime95 is very hard on the CPU and APM doesn't like it. So you will likely see 3.5->3->3.5 oscillation. With more "normal" programs, you shouldn't see that.

Once you 're done edited your P-States, save the values in the .txt and rename the .txt file in .bat. Move the bat to the folder where your executable of AMDMrsTweaker is. Run the batch file once as administrator to start stress testing.

Now, how to stress test each P-State. Open PSCheck and CPU-Z for verification. PSCheck has some blue arrows on top. These move between P-States and lock them while there. Once you locked a P-State, you can run stress test. Example stress testing [email protected]:

In case you want to change a value, go back to the bat file, rename its extension to .txt, edit, rename in .bat and repeat testing.

6) Go to start. Type "task scheduler". Fire it up. "Create New Task". Under "General" Tab: Name "AMD Mrs Tweaker". Tick "Run with highest Priviledges". Click "Change User or Group", type "SYSTEM" (without the ""). This is important, in order for the batch file to run hidden at boot, otherwise you see a command line window at every boot. It took me a while to find this solution.

Under "Triggers" : Begin the task: "At Log On". Make sure the "enabled box" is ticked.

Under "Actions" : Action: Start a Program. In the program/script field: C:\AmdMsrTweaker\AMDMsrTweaker.bat

Under "Conditions": uncheck every box.

Under Settings: Tick "Allow to be run on Demand", "Run task as soon as possible..."If the running task does not end as requested". UNTICK all the rest.

Now, make sure your task is "enabled" in the task scheduler list (shows as "ready") and reboot.

Hopefully, you should now have the batch file running in background at every boot. To verify use CPU-Z, or run the executable of AMDMsrTweaker or PSCheck.

At the end, you have something similar (see PS Check):

I hope it helps. It took me a while to figure everything out, since the original threads of the author that i found googling are a bit chaotic, but for reference and kudos, are here:



DISCLAIMER : Please, if you don't understand anything in this topic, don't try it. Also, please understand that every motherboard/CPU is different. I am not responsible if you have instability problems. I posted my values only as example. This is why i can't stress enough, that you must do your own stress tests for EVERY P-State you want to change. The values above, work on my FX6300, but are NOT fully optimized for maximum undervolting. I used quick guesstimates based on my experience with K10Stat and i decided to keep them until i have more time, since they all worked on the first try.

A very big personal thanks to the program's author. I was almost suffering from the lack of a K10Stat equivalent.

OF COURSE, the program allows also to change the frequencies of the P-States to one's desire, by changing the multiplier. For example if instead of P6=7 , ones puts P6=6, the frequency will be 1200Mhz.

Good luck!


Here's a string line for [email protected] (with Cool N Quite enabled. In Giga UD3P, APM is OFF, Turbo is auto): [email protected] [email protected] [email protected] [email protected] [email protected]

Ryzen 2600 - MSI B450 Gaming Plus - 16GB Corsair 3000Mhz C15 - GTX 750Ti
Undervolter is offline