Radeon HD 7950 Owner's Thread

[Silverforce11]

I've been having a hard time overclocking my Gigabyte WF3 7950. This card has a low default VCore of 860mV and will stutter in gamers very badly even at 975MHz Core. Upping the VDDC to 1000mV (via Afterburner) allows smooth 1GHz speed (haven't tried going further) but, after a while, the card defeats the Afterburner settings and reverts to the 860mV VCore. The OC setting is maintained however so it's a stutter-fest. Uggh!

I'm thinking of updating the BIOS but am confused on what version is accepted by my card (which uses 2x6-pin PCI-e connector, with BIOS version F10). It seems there are specific BIOS versions cards with this BIOS can use and cannot use. I'm not even sure if any of the newer BIOS will fix the ridiculously low VCore.

Can anyone help me?

Thanks.

That cannot be right.. the 0.86 vcore is in idle mode, so if you read it at desktop it may give u that. You "raising" it to 1.0v is actually substantially down-volting it, as 7950s typical vcore are 1.1v+, for boost edition its even higher with reference designs at 1.25v.

As far as i read around on a lot of forums, the lowest default vcore on 7950s is 1.07v and as far as i know, only the PCS+ models have it this low, the rest being 1.125v or above. Suggest you disable AfterB and let your card go real default and test stability.. or try Sapphire Trixx instead.

 

[zaydq]

That cannot be right.. the 0.86 vcore is in idle mode, so if you read it at desktop it may give u that. You "raising" it to 1.0v is actually substantially down-volting it, as 7950s typical vcore are 1.1v+, for boost edition its even higher with reference designs at 1.25v.

As far as i read around on a lot of forums, the lowest default vcore on 7950s is 1.07v and as far as i know, only the PCS+ models have it this low, the rest being 1.125v or above. Suggest you disable AfterB and let your card go real default and test stability.. or try Sapphire Trixx instead.

Sounds like Silverforce is right, that is nearly impossible to be running under 1v at that clock speed. I don't think the bios is your issue for this, sounds more like AB isn't functioning properly, or you have conflicting software going on. is CCC's overdrive enabled?

 

[hjalti8]

Is there anyone who knows which gigabyte 7950's are voltage locked?

These gigabyte models are really cheap where I live so I am probably gonna buy a second one for mining.

I can choose between a 900mhz one and a 1000mhz one. The 1000mhz one is locked right?

Also I have heard you need to flash to another bios on some of these cards to get the most out of them. I have no idea how that is done and it would be much appreciated if you guys could point me in the right direction

 

[Belkov]

Revision 2 gb 7950 wf3 are hardware voltage locked. bios versions F3, FZ1, FX0, FW0 and i think - FX1 and FY1(i'm not 100% sure for those because i could not reflash them on my VGA), are GHz bioses and they are software voltage locked. My opinion is that F43 bios version is the best for now. If you take a card with 900/1250 stock clock, you can be almost 100% sure it is not hardware voltage locked.
The most secure way to reflash is using atiflash under DOS. You can see how to do it here.

 

[hjalti8]

wow thats a lot of info there belkov, thanks!

 

[Belkov]

No problem - live to serve...:biggrin::biggrin::biggrin:

 

[aaksheytalwar]

Aren't all gigabyte 7950s voltage locked?

 

[Belkov]

No, not all of them are voltage locked. Some come with voltage locked GHz bioses, but you can easily unlock the voltage by reflashing the bios. Only the newest GB 7950 WF3 are hardware voltage locked.

 

[hokies83]

Power Color Boost state is locked to ive tired over 40 Bios and none would flash to the card.

 

[Zorander]

That cannot be right.. the 0.86 vcore is in idle mode, so if you read it at desktop it may give u that. You "raising" it to 1.0v is actually substantially down-volting it, as 7950s typical vcore are 1.1v+, for boost edition its even higher with reference designs at 1.25v.

As far as i read around on a lot of forums, the lowest default vcore on 7950s is 1.07v and as far as i know, only the PCS+ models have it this low, the rest being 1.125v or above. Suggest you disable AfterB and let your card go real default and test stability.. or try Sapphire Trixx instead.

My initial OC attempt involved upping the Core to 950MHz (factory default is 925MHz) via CCC and that failed miserably in stutters and hard freezes. Upping the power setting to 20% saw no positive result either. I attributed it either to bad cooling or GPU with bad OC potential. I gave up at that point.

I decided to try again last week, this time using Trixx (and alt-tabbing out of games to quickly check readings in GPU-Z). That's when I discovered the low VCore values (and temperatures were only around 60C). Upping the VCore to 1000mV got rid of the stutters but I soon discovered the card will somehow revert to the low VCore values after a while. I can 're-apply' the OC settings and it will revert again in time and soon it becomes a frustrating cycle. AB seems to maintain the OC settings a little longer but it's still the same story in the end.

I'm using Catalyst 13.1 but I'm convinced it's a lousy BIOS setting that causes all of this. I'm thinking to update the video BIOS (to F43, as pointed out) but wary that only certain BIOS versions are accepted by my F10 card. Obviously I don't want to brick my card with the wrong BIOS.

Thanks for the input.

Edit: I'll try upping the VCore to 1.1V later tonight and see if it changes things. That should be safe, I assume?

 

[Face2Face]

That cannot be right.. the 0.86 vcore is in idle mode, so if you read it at desktop it may give u that. You "raising" it to 1.0v is actually substantially down-volting it, as 7950s typical vcore are 1.1v+, for boost edition its even higher with reference designs at 1.25v.

As far as i read around on a lot of forums, the lowest default vcore on 7950s is 1.07v and as far as i know, only the PCS+ models have it this low, the rest being 1.125v or above. Suggest you disable AfterB and let your card go real default and test stability.. or try Sapphire Trixx instead.

My first TF3 had a stock voltage of .993v and would do 1000Mhz on it. It had a ASIC of 93%. My current TF3 has a stock voltage of 1.030v - with V-droop it's under 1.000v @ 1025 Mhz. That's as high as it will go with the stock voltage. My current card has an ASIC of 89%. Here on this thread there are a couple of people that have reported stock voltage that is under 1.000v most with a 7970 PCB MSI TF3. You won't see these voltages with current 7950's as they are all using lower ASIC chips.

 

[Tattoedsailor]

Just got Sapphire 7950 Asic quality is: 55.6 Not sure if that's good or bad

 

[Face2Face]

Just got Sapphire 7950 Asic quality is: 55.6 Not sure if that's good or bad

Hey Joe, is that you?

55.6 is not that great, but it's becoming the norm these days. Shouldn't affect it's overclocking ability. Ramp her up and see what she can do

 

[Tattoedsailor]

^^ yeah its me. Not as good as MSI. MSI was @ 60.

 

[futurefields]

weeooo got my Sapphire 3L model today, a day early from Newegg! Must be my lucky day.

promptly installed her, which went fine. it fits nicely in my Antec 300 with about a half inch to spare. fired up Far Cry 3, and im now getting better framerates running Ultra settings + 4x msaa than my 6850 got on High settings with no msaa. pretty happy about that. temps at idle are 25 celcius and after a half hour running around the island on Far Cry 3 it was 52 celcius, what do you guys think pretty good temps? those are stock settings 925 core 1250 mem

 

[Belkov]

yes - it's nice temp. Try to clock and see what are the temps then.

 

[Stuka87]

^^ yeah its me. Not as good as MSI. MSI was @ 60.

It varies from card to card. No single manufacturer gets higher quality chips than another from what I have seen.

 

[Tattoedsailor]

Hey Joe, is that you?

55.6 is not that great, but it's becoming the norm these days. Shouldn't affect it's overclocking ability. Ramp her up and see what she can do

I ended up returning it. Pretty sure there was something wrong with. I benched it @ stock settings on Crysis 3 was getting horrible FPS (like down in low teens). The MSI I benched was stable @ 30-40 FPS. I'm not spending that kind of money and having a dud!

 

[aaksheytalwar]

I ended up returning it. Pretty sure there was something wrong with. I benched it @ stock settings on Crysis 3 was getting horrible FPS (like down in low teens). The MSI I benched was stable @ 30-40 FPS. I'm not spending that kind of money and having a dud!

A low aisc doesn't get lower fps.

 

[Tattoedsailor]

A low aisc doesn't get lower fps.

Agreed, but thats not why I returned it. Its obvious there was defiantly something wrong with it.

 

[Face2Face]

Agreed, but thats not why I returned it. Its obvious there was defiantly something wrong with it.

Sounds like there was. Hopefully the next one will workout for you. Let us know.

 

[Belkov]

What brand will be the new one?

 

[Tattoedsailor]

What brand will be the new one?

:thumbsup: HIS 7950 Iceqx2. I noticed the power requires 1x6 pin and 1x8 pin. What is the difference between this and 2x6 pin?

 

[zaydq]

:thumbsup: HIS 7950 Iceqx2. I noticed the power requires 1x6 pin and 1x8 pin. What is the difference between this and 2x6 pin?

it means the card is built on a reference 7970 PCB and can handle more voltage than the 7950 6+6 pcb.

 

[BallaTheFeared]

Hey guys, I dunno if this is well known or not, but it's annoyed me since getting my 7950...

Using MSI I can only overclock with forced constant voltage, however when it downclocks it's downclocking only, it's not undervolting.

If I don't force voltage than I'm stuck at 1.25v, however if I force my voltage that I want, then turn it off and reboot it will actually boot in with that as the default vid.

I don't know if it keeps it through multiple reboots or not, I haven't got that far. However it does drop to 800mv with the ultra low clocks as well now and I got my voltage set for 1050MHz and it's working right - ie not at 1250mv :\