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

tommybhoy · 1 May 2013 at 01:59

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).

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

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.

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:

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:

2. Open VBE7.

3. Load your bios.

4. Select the OverDrive & PowerTune tab.

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

***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 '#':

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):

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. :cool:

^
***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:

+30% Power Control/Limit No SPiking:

LtMatt · 1 May 2013 at 07:07

Good stuff Tommy should really help people with boost cards that have stuttering problems.

shankly1985 · 1 May 2013 at 07:43

Nice find
Not something I willing to try just yet though lol

pgi947 · 1 May 2013 at 07:46

Gonna be all over this like a fat kid on cake

Mmmm 50% limit at 1.38v.

IRLeetly · 1 May 2013 at 08:50

Very nice, but I don't think I'd like to risk it. I'll let some folks try it out on the 7800 series first

~Mike~ · 1 May 2013 at 08:56

Nice Tommy, not for me as I wouldn't want to take the risk.

pgi947 · 1 May 2013 at 09:10

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

If so maybe some titan owners should get looking for an nvidia way of doing this...

Zeed · 1 May 2013 at 12:56

uuuu i will defo get that going. My watercooled 7950 can take it no problem after my last radiator upgrade

Zeed · 1 May 2013 at 17:00

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

tommybhoy · 1 May 2013 at 20:18

Thanks lads.

pgi947 said:
So in theory this should increase the tdp limit by 30%?

It does indeed.

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

pgi947 · 1 May 2013 at 20:52

tommybhoy said:
Thanks lads.

It does indeed.

If my absolutely terrible math is anything to go by, that takes a 7970 up towards 300w TDP!!

Suarez7 · 1 May 2013 at 22:02

So will this help get higher clocks? I can recall seeing this 50% trick a while ago on the 6 series and iirc correctly it didn't actually do much apart from break peoples cards.

Suarez7 · 1 May 2013 at 22:36

Testing 50% now, GPU load seems much more consistent.

Zeed · 2 May 2013 at 12:57

Suarez7 i bet cards that fried ware air cooled....
I dont think u need whole 50% tho i am happy with that extra 35%... I would need to run some benchmarks on 20vs30vs40 and see whats the sweet spot

shankly1985 · 2 May 2013 at 15:35

Can we get some benches going

I would but scared seeing some you guys already done test could you benchmark it?

Thanks

imginy · 2 May 2013 at 15:42

pgi947 said:
So in theory this should increase the tdp limit by 30%?

If so maybe some titan owners should get looking for an nvidia way of doing this...

nvidia owners can already do this with a simple bios update

Also just because you put the number higher doesn't mean the card will increase by the same amount, the actual increase will probably only be extra 5-10%.

Suarez7 · 2 May 2013 at 16:30

Card hasn't melted yet.

cainer · 2 May 2013 at 18:18

Suarez7 said:
iirc correctly it didn't actually do much apart from break peoples cards.

Suarez7 said:
Testing 50% now

fishingcat · 2 May 2013 at 20:42

Anyone know how to get this working on Windows 8?

It doesn't seem to have worked for me.

fishingcat · 2 May 2013 at 21:01

I take it back, this tweak does work on Windows 8!

Turns out I missed a step.

Time to see how far this HD 7870XT can go!

EDIT: Initial results are positive. The card is maintaining it's boost state frequency for more of the time, and still appears stable. Temperatures appear unchanged.

EDIT 2: Wait, can't go above 25% without artifacting. This GPU is pretty finicky with voltages and clocks though, so I'm not surprised.