AMD - How to Change The Power Control/Limit from +20% to +50%

[tommybhoy]

How to Change AMD's Power Control/Limit from +20% to +50%

Method 1 Software Mod

This method makes zero hardware/bios changes to the factory settings of your gpu, it is strictly a Windows/AMD CCC software mod:

Tested on W7 and W8.


Here's how to mod the Power Control/Limit in single card mode and CrossFire mode(You can possibly by pass a lot of this by selecting 'Extend official overclocking limits' within AB and just modify the reg file):

***WARNING-Do So At Your Own Risk!!!***-WARNING

***WARNING-Don't Go Straight For +50%!!!***-WARNING

***WARNING-Don't Blame Tommy If You Do Anything Silly!!!***-WARNING



1. As you are going to modify the Catalyst reg entry- switch on System Restore(if it isn't already) and make a new restore point-just in case.

2. Install Afterburner if you haven't already as you will need it to activate the reg entry and reboot:

http://event.msi.com/vga/afterburner/download.htm (I used the latest version 3.0.0 beta9)

(skip this step if AB is already installed).

3. Create a new AB shortcut and add '/xcl' at the end of it(without the quotes)save, then run it as administrator(This edits the Powerplay Tables) and you should get a 'limits increased' message(or similar, I can't remember the exact message).

Spoiler

4. Open 'regedit' as administrator-right click and 'run as administrator':

Spoiler

5. Browse to:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E968-E325-11CE-BFC1-08002BE10318}\0000

^
It might not be 0000, mines was 0006

6. Export and save the entry(and also make a back up also in case of problems), this is the file you are going to edit to change the 20% value to 50%.

7. Open your reg file with notepad and find and edit the following value in 'PP_PhmSoftPowerPlayTable':

Look down about 4 lines and you'll see the number 14 in between a bunch of zeros and change the 14 to a 32, making sure not to change anything else at all!

8. Close and save it as 'Power Limit mod' or similar.

9. Right click on your modified reg entry and and allow it to 'merge' then reboot-if using a single gpu, more step(s) for CrossFire users.

10. CrossFire only Find your other gpu and export the reg entry again, open it and copy your modded 'PP_PhmSoftPowerPlayTable' values into this reg entry-there is no 'PP_PhmSoftPowerPlayTable' to begin with you are manually adding your existing value from your first gpu.

Original file should look like this:

"AdapterDesc"="AMD Radeon HD 7900 Series"

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E968-E325-11CE-BFC1-08002BE10318}\0007\DAL2_DATA__2_0]
"default"=hex:64
"All_displays"=hex:31,30,00

After you copy the 'PP_PhmSoftPowerPlayTable' values, it should look like this:

"AdapterDesc"="AMD Radeon HD 7900 Series"
"PP_PhmSoftPowerPlayTable"=hex:1d,02,06,01,00,00,00,10,18,58,00,6c,00,ee,00,e8,\
03,e8,03,58,00,00,80,03,00,10,00,00,02,07,3b,00,00,6e,00,f0,00,05,50,01,0a,\
00,5f,01,6f,01,e0,02,00,00,90,13,00,00,7b,01,9a,01,b4,01,00,00,ec,01,00,00,\
c3,00,00,00,82,00,00,00,60,ea,00,00,d3,01,08,07,00,00,32,00,40,00,04,01,00,\
00,04,01,04,05,06,00,03,02,05,05,06,03,03,07,07,07,08,10,54,69,01,48,e8,01,\
02,ff,6b,03,02,00,00,00,00,00,50,c3,00,80,38,01,20,03,5c,03,01,00,00,00,00,\
00,30,75,00,80,38,01,20,03,5c,03,01,00,00,00,00,00,40,9c,00,80,38,01,20,03,\
5c,03,02,00,00,00,00,00,30,75,00,98,3a,00,b6,03,6b,03,00,00,00,00,00,00,b4,\
c3,00,48,e8,01,b6,03,6b,03,01,00,00,00,00,00,08,4c,01,48,e8,01,01,ff,6b,03,\
02,00,00,00,00,00,30,75,00,98,3a,00,20,03,6b,03,00,00,00,00,00,00,04,18,08,\
00,00,00,78,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,05,00,\
00,00,78,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,04,00,\
00,7a,00,00,00,00,00,00,a0,86,01,00,f8,24,01,00,00,00,00,00,00,00,00,00,00,\
78,00,00,00,00,02,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,65,03,62,66,\
05,63,67,07,64,68,0a,68,68,09,02,06,88,13,34,21,e4,25,b8,0b,70,17,1c,25,e4,\
25,0c,00,64,8a,02,00,e8,6e,03,00,f5,01,06,30,75,00,20,03,50,c3,00,84,03,60,\
ea,00,ac,03,70,11,01,b6,03,08,4c,01,01,ff,54,69,01,02,ff,05,98,3a,00,5c,03,\
30,75,00,61,03,70,11,01,66,03,48,e8,01,6b,03,ac,e8,01,6c,03,06,98,3a,00,20,\
03,30,75,00,84,03,70,11,01,ac,03,48,e8,01,b6,03,ac,e8,01,01,ff,10,e9,01,02,\
ff,04,20,03,00,00,00,00,b6,03,00,00,00,00,cf,03,00,00,00,00,20,04,00,00,00,\
00,01,e8,03,98,3a,00,a8,61,00,00,03,d8,d6,00,d8,d6,00,70,11,01,70,11,01,30,\
75,00,30,75,00,02,b6,03,00,1a,04,01,06,01,01,00,01,02,02,00,01,02,03,00,03

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4d36e968-e325-11ce-bfc1-08002be10318}\0001\DAL2_DATA__2_0]
"default"=hex:64
"All_displays"=hex:31,30,3b,39,00

(Don't use the above settings, these are my modded bios settings for my 7950 Boosts(that removes the boost)-use your own settings or bad things may happen!!!)

You need to use your own settings, worst case scenario if you have 2 different Asics, you run the risk of putting far too much voltage through a high Asic gpu causing possible damage or killing it full stop.


You need to add the entry for each card you have, then reboot.

Spoiler

Open AB and you should be able to select up to 50% in the 'Power Limit' slider.

After the above method activates the limit, you can use CCC, Trixx and His iTurbo(-50% should be selectable too)with the increased limits also.

Hopefully you should be able to see this:

Spoiler

You may have to activate 'Force Constant Voltage' within AB.

No further steps required for CrossFire.

If you have any problems, restore the original reg file in safe mode or use System Restore.




Method 2 Bios mod/Bios Flash

In case you missed it the first time:

***WARNING-Do So At Your Own Risk!!!***-WARNING

***WARNING-Don't Go Straight For +50%!!!***-WARNING

***WARNING-Don't Blame Tommy If You Do Anything Silly!!!***-WARNING

***WARNING-Don't Change Any Other Values In VBE7 Unless You Know What You Are Doing!!!***-WARNING

(There is an element of risk involved here, please be sure you have a twin bios card as you have one to fall back on if something goes wrong)

***So far, resume from sleep does not work using this method on the His 7950 Ice-Q's-other cards may suffer from this also***



This method requires you to modify the Power Limit from your cards original bios requiring a bios flash:

Tools needed:

gpuz

VBE7 vbios editor

1. Open gpuz, save your bios:

Spoiler

2. Open VBE7.

3. Load your bios.

4. Select the OverDrive & PowerTune tab.

5. Modify the setting 'TDP Limit (%)' from 20 to 50.

Spoiler

***Just in case you noticed different clock speeds-I just used example picks I had to hand, the 'TDP Limit (%)' is all you change for the Power Control/Limit!***

6. ***Optional-Remove the Boost-skip to step 8 if you don't want to remove boost clocks***-Select the Powerplay tab.

7. Change value '#' to match whatever value is in '#':

Spoiler

8. Save your modified bios for flashing to your gpu:

Bios Flashing Instructions(all credit to LtMatt as I used his guide with a tiny adjustment):

Spoiler

LtMatts Bios Flashing Guide:

You might want to write this down...

You need to create a bootable usb stick.

1. Download and install the USB disk format tool here.

2. Download the Windows98 system files here.

3. Create a folder called Win98boot on your desktop, extract the files from step 2 into the folder.

4. Plug in your usb stick. Launch the USB disk format tool. Copy these settings, then click format. You need to select quick format, tick dos startup and select the Win98 folder, like ive done below.

5. Click start, then ok and it should do it.

6. Download atiflash. Extract it onto the usb stick.

7. Copy your modified bios into the usb stick-For the purpose of this guide, the modified Power Limit bios file is called Matt.rom(yours will be called whatever you named it).

8. If you've done everything correctly your usb stick folder contents should look like this. (except the bios should say Matt.rom instead of HIS7950.rom) Do not worry if you have more or less files than what appears in the screenshot. As long as you have the bios file and atiflash thats all that matters. Windows 8 users might have extra files like in my screenshot.

If you look to have a file or two missing it could be because you don't have show hidden files ticked in control panel, folders.

9. Make sure all gpu's in your pc are switched onto bios 1.

10. Uninstall gpu drivers and any overclocking apps. Do not keep settings delete everything.

11. Restart your pc. Before you hear the beep keep tapping F8. Boot from the usb stick.

12. You should be at dos prompt. Type atiflash -i to get the adapter number for both your gpu's. Typically it will be 0 and 1, unless you have a gpu in a third pci-e slot. You need the adapter number to tell it which gpu to flash.

13. To flash gpu 1 type atiflash -p -f 0 Matt.rom and hit enter.

Wait for it to finish. It will prompt you to restart but before we do that we need to flash the second gpu as well.

Now do the second gpu (if you have one)

Type atiflash -p -f 1 Matt.rom

Once that has completed and you get a notification saying you can restart press Ctrl+Alt+Delete to restart your pc.

All going well you should get a display and boot back into windows. Now you can reinstall fresh new drivers etc. You have the option to select 50% power setting as standard with every driver install.

If something goes wrong and you get no display from the cards after flashing the bios. Turn the pc off and flick both cards bios switch to position 2 to use the stock backup bios. Turn the pc back on and all will be ok.

Good luck.

^
***A few are having problems with the tool for creating a bootable usb, you can try this alternative app to format your keydrive into a USB boot disc if the one in matts guide is causing problems***

Alternative_Bootable_USB_Drive_Creator_Tool


***Run the app and point the tool to 'USB Drive Boot Files' then 'MS-DOS', create your boot disc then add ATIflash and the bios .rom of your choice.***








The above can help negate boost/Ghz clock spiking/droops should your gpu suffer from it, by increasing your Power Control/Limit.

+20% Power Control/Limit GPU Spiking:

Spoiler

+30% Power Control/Limit No SPiking:

Spoiler

 

[tommybhoy]

Thanks lads.

So in theory this should increase the tdp limit by 30%?

It does indeed.

Update its working got it at 35% will test out later. Thanks for gr8 hax

 

[tommybhoy]

I cant see any big gains in points I ran tests many times and well it does not seem to give us any points.

The Power Control on it's own won't give any more points.

 

[tommybhoy]

good find....might try to get rid of some of that vdroop i get under load atm. Did you find it helped keep your top OC voltage steady?

Much better at keeping the voltage where it should be, I was suffering from those spikes in the above AB gpu usage shots with both gpu's in some titles even@stock, but that's using the 'Boost' bios.

Stable clocks are up 10-20MHz, not much but I'm on air, proper full plate WC'ing may yield better gains.

 

[tommybhoy]

OP updated for CrossFire reg entries.

So by rights increasing this should allow you to increase the cards Overclock with a lower voltage increase?

Yes, it does, I can do 1100/1450MHz on 1125mV +35% now.

 

[tommybhoy]

^
Lol.

It's enabled better/smoother gpu usage definitely, the horrid boost spikes are no more.

 

[tommybhoy]

Well done Suarez on helping out matt.

Updated the op again-for a clearer explanation on merging the reg entry.

 

[tommybhoy]

^
Regedit>Edit>FindP_PhmSoftPowerPlayTable

Should take you where you want to go.

 

[tommybhoy]

thanks tommybhoy unlocked the power limits but still cant get control of my voltage on my 7950 iceq boost 1.25v only when boost kicks in

Have you tried His iTool and Trixx for voltage adjustment?

Can't remember if you wan't the voltage to increase or decrease either.

can you get away with an overclock of 1100/1500 on a 7950 without 20% on the power slider (leaving it at 0)

Card dependant, some will, some won't, but it's probably more dependant on voltage over what the power limit can do.

 

[tommybhoy]

okay on my 7950 i have 1050/1575

with just the 20 percent added only using ccc overdrive at mo.

i haven't touched the voltage . temps seem very nice aswell.

new to oc these 7950s so any help would be appreciated

If it's just for playing games, then if you can push to 1100MHz on the core, your in a good place not having to muck about with any other OC tools, the extra Power Limit, may help.

If you want max clocks, it's just the same as any other card, find the limit on the core first then dial back a bit checking stability with Heaven or a hard hitter like Sleeping Dogs.

Reset core to stock and repeat on the vram, then go for both clocks applied adding voltage if you can/want to push even further.

If you want to add voltage, then matt's thread has everything you need to know:

http://forums.overclockers.co.uk/showthread.php?t=18431335

Ok, was just wondering if at 0% i would get lower temps than at 20%

Test it with and without Power Limits, use Gpu-Z and click the temp sensor to maximum, stress the card and you'll find out.

 

[tommybhoy]

^
I'm presumming it works the same as CrossFire Diagro, you modify your original PP_PhmSoftPowerPlayTable settings in 0000(or whatever yours may be), and copy and add(as they don't exist) said PP_PhmSoftPowerPlayTable settings to 0001(or whatever yours may be) after the line-"AdapterDesc"="AMD Radeon HD 7900 Series"

This will disable ulps/switch off zero core though.

 

[tommybhoy]

Over to master tommy for assistance.

@Diagro, if your doing a new install and can afford a gimped registry, my easy answer to your question is to add the PP_PhmSoftPowerPlayTable settings to all of them.

I don't think it will do any harm anyhow(but could be very wrong) but as long as you back up each reg setting, then I don't see how you couldn't launch into safe mode and restore each value.

Spoiler

 

[tommybhoy]

Np,

Just don't go whacking it up to 50% in a hurry, ~+30/+35% is probably where it needs to be.

 

[tommybhoy]

Probably matt, at the price they have been going at, there must be plenty more getting setup now.


Op updated btw-don't copy my data tables as both gpus in those tables are low Asic gpus(yes I left a hint there for the crazy folks with selective reading), modify your own.

 

[tommybhoy]

Try swapping the cards round to confirm it's the boost at fault.

Test the normal limit (+20%)temps on a loop of Heaven BM, take a note, then try out the +45% temps on the same loop of Heaven BM and compare, if the temps are similar, then it should be good to go as the Limit hack afaik can't push the TDP value further than what is set in the bios.

 

[tommybhoy]

Big update to the OP, added a Bios Mod guide using VBE7 for a more permanent Power Control/Limit Fix.



Matt, hope you don't mind I used(and changed for this thread) your bios flashing guide.

 

[tommybhoy]

Why do you say don't jump to +50% power limit in the guide? There should be no risk to doing so

Twofold:

I'm not an Amd engineer and don't know for sure there would be any long term damage (if any) running at +50% and don't want any grief for anything that goes wrong by doing so.

A much higher chance of introducing coil whine kicking in too running at 50%.

The main aim of the thread was to negate boost spiking, higher oc's was just a bonus tbh.

is there seriously no way to PM someone on this forum? Tommybhoy, answer me goddamnit.

I wrote a guide with your info in it too:
http://www.overclock.net/t/1394623/belials-comprehensive-guide-to-7950s/0_100

If you read the FAQ, it would tell you to use the trust function to send pm's.

Nice guide btw.

 

[tommybhoy]

wut? This sounds completely made up. If you mean by there's a higher chance of introducing coil whine, or you really mean VRM overheating, not coil whine, coil whine is a byproduct of overheating VRM

Not made up at all, first hand experience of applying 40-50% introduced coil whine when there was never any instance at all.

if I thought it was anything to do with vrm temps I would have laid mention to them as a possible cause, at a guess the higher limit was putting more stress on the psu rails causing the whine.

Again my aim in the thread was to negate spiking, not to introduce any other problems.

 

[tommybhoy]

Are you really giving him grief just for telling people to be careful?

It's looking like it.

What can I say, just checked out the Anand/Oc.net threads and it's pick a fight time in every other post.

http://forums.anandtech.com/showthread.php?t=2352365

http://www.overclock.net/t/1394623/belials-comprehensive-guide-to-7950s

And my guides been used and modified to more or less-'whack it up to 50%'-all credit to tommybhoy, but since I'm not a member of those forums I'll not say too much about it.