7970m crossfire overvolt

Hi there guys, since the 980m is currently not a viable option I wanted to inquire if anyone has ever tried to overvolt the 7970m and with which results.
Currently I can easily overclock to 850 core and 1400 memory.
what could one expecr from overvolting the cards? Is it worth the risk?

Also I haven't done it before, I presume the whole thing won't be done in windows so any hint into the right direction would be very appreciated!

Cheers!

 

Try getting the core up... I would say, as long as voltage is on 1.1V, you'll be fine.. You don't want to do more than that for daily usage...

 

In my experience overvolting to 1.1v gave me an extra 20MHz on the core and that was it, so for daily use not worth it but for number chasing I would put up with it.
It depends what you are trying to do as well, if your trying to squeeze every last drop out of the cards then yeah you will need to overvolt. If you just want a bit of a bump see how far they go on stock voltage.... remember you will get more life and less heat if you can avoid overvolting.

How are you overclocking at the moment?

 

I believe I got to 950/1350 on stock 1.050 voltage, never bothered to overvolt because the 7970M is such a temperamental card, and dies for no reason even when temps are very reasonable. My R9 M290X can achieve 1000/1400 on stock 1.050 voltage.

 

R9 290MX is better binned then 7970M... Your stock 1.05V scores are similar to mine with 1.05V.. I used to go up to 950/1400 at 1.05V.. A trick to slightly improve the performance is to make the TDP limit from 84-100W in the BIOS to 100W so you get max performance under load... You need to mod vBIOS to do (takes 5s to do it)...

 

Each core seems to like different voltages, some do well at stock but don't move with extra voltage, some like voltage all the way up to what you can get and some prefer just a small jump.

You need to go through and try different settings.

 

What program do you use?.... svl7's vbios patcher?

 

P

I am using the Msi afterburner.

Tom if it really takes only 5s would you care to elaborate?

 

Msi afterburner works great for finding you limits etc but if are wanting to overclock for every day use modifying your clocks/voltage in the vbios is the best (most stable) way to do it.

If you head over to techinferno, svl7 has made a whole set of modified vbios's for the 7970m both overclocked and overvolted with different combinations, he also has made an easy to use vbios patcher for the 7970m so you can customize your vbios if you want to. On top of that he has provided all the instructions for flashing and creating a bootable usb which you will need in order to flash you cards using atiflash.
A google search for "7970m modified vbios" and "7970m vbios patcher" will bring up both threads.

 

Well my method was a bit dangerous

I use VBE7 to edit the vBIOS: the change you need to make for TDP in powerplay section I believe : http://www.techpowerup.com/forums/threads/vbe7-vbios-editor-for-radeon-hd-7000-series-cards.189089/

I flashed the vBIOS with ATI Winflash and I wouldn't recommend it: In the 5 BIOS flashes I performed, 3 failed.. I had to try weird stuff for the flash to finish properly. If I had lost power, bye bye 7970M..

The safe way to flash is in DOS: http://forum.techinferno.com/amd-video-cards/1738-[guide]-amd-vbios-flashing.html

 

If DOS is an option, ALWAYS take it

 

I get shut downs with any voltage above 1.050, so I don't know if its the cards or the CPU that is consuming too much power, so I just keep it at 1.050 or 1.025V. I have also over clocked my base/battery/2D clock to 350/300 instead of 300/150 at 0.825V

 

It wont be a power problem, I have had my cards at 1.1v (990/1475) and cpu at 4.7ghz drawing (110Watts) with a total system draw of 325watts
Some cards don't take extra voltage to well, so long as it can handle the stock 1.05V then that's fine.

 

Yes there seems to be a huge range of reactions from different GPUs. Some love just a step or two more voltage, some like it all and some will just refuse to work with extra. I think it's just variation in the silicon itself.