XFX 7900GT Owners - Light at the end of the tunnel

[scrandman]

OK - mine had the crazy artifacting after a couple of days at the stock settings (520 / 1500). I downclocked it to standard 7900GT settings of 450 / 1320, and contacted XFX support. Two replies and a fortnight later (boy they're slow) they suggested the following fix:

Increase the memory speed by 5 mHz using Coolbits, or use the optimal setting. I reset the core to 520 and memory to 1500, then bumped the memory speed up by 5 mHz (i.e. 1510). I was sceptical to say the least.

Crazy thing is, it appears to have worked!

They did ask for the serial number of my card before they suggested this, so it might not be a fix for all artifacting cards, however after an hour of testing it does look good on mine.

Can't think why this would work, unless it is a memory timing issue, and increasing the clock automatically increases the timings / latency of the memory.

I will be watching my performance closely for the next few weeks and will post back if any other issues arise.

[Max Tractor]

http://forums.hexus.net/showthread.php?t=76334&page=3

my findings post 33

[scrandman]

What do you mean by throttling? RivaTuner shows it running at the correct speeds.

[Max Tractor]

Throttling means it slows itself down. I have also found in 03 that if the clocks are not correct, prior to it throttling, the screen goes grey or black, then it will continue it run

[scrandman]

Yep, thought that's what you meant. Doesn't appear to be the case here though. Running RivaTuner in the background while running 3DMark03 shows a constant 518 for all 3 aspects of the GPU core and 756 for the memory clock. More importantly, still no signs of the artifacting.

Could it be that the stock clocks are dodgy (as per your experience), but tweaking the memory clock op a tad fixes this?

[jimborae]

OK - mine had the crazy artifacting after a couple of days at the stock settings (520 / 1500). I downclocked it to standard 7900GT settings of 450 / 1320, and contacted XFX support. Two replies and a fortnight later (boy they're slow) they suggested the following fix:

Increase the memory speed by 5 mHz using Coolbits, or use the optimal setting. I reset the core to 520 and memory to 1500, then bumped the memory speed up by 5 mHz (i.e. 1510). I was sceptical to say the least.

Crazy thing is, it appears to have worked!

They did ask for the serial number of my card before they suggested this, so it might not be a fix for all artifacting cards, however after an hour of testing it does look good on mine.

Can't think why this would work, unless it is a memory timing issue, and increasing the clock automatically increases the timings / latency of the memory.

I will be watching my performance closely for the next few weeks and will post back if any other issues arise.

Mate you are a star !!!

I did the same as you & it's cured my artifacting problem too. I think it's obvious that XFX need to release a new bios for this card.

[cpuchimp]

Don't hold your breath! I think there is a flaw in the chip.

[jimborae]

Wierd thing is I just out the clocks back to standard to try & post some screenshots & it isn't artifacting now at the standard clocks like it was before.

Hmm the plot thickens

[scrandman]

Glad to see I'm not an isolated case

Anyways, I'm not even going to try going back to stock settings

BTW: Which model are you running. Mine is the 520/1500 version with the metal bar along the top of the card, which means it is the latest revision (I think). Part number from the box is PV-T71G-UCER.

[jimborae]

Don't hold your breath! I think there is a flaw in the chip.

If it is a hardware problem isn't it likely that it's more to do with memory chips rather than the core?

The next time I have the pc out I'll compare my two XFX cards and see if the memory chips are different. They are slightly different model numbers

PV-T71G-UCER : has a free copy of COD2 included
PV-T71G-UCE7 : no free copy COD2

But both say Ver A.0

[scrandman]

Mine had the freebie COD2 as well.

[Agent]

Don't hold your breath! I think there is a flaw in the chip.

Im not so sure (if it was, we could expect to see a simlar situation with the GTX range which are basicly the same core) - but regardless of whats to blame. If a 5mhz addition to memory clock speed is all thats needed, this is simply a easy modification for the cards BIOS.

Heck, i used to do some basic nVidia BIOS editing (i dont know how much it has changed since the geforce FX days though) - if any of you guys want to dump the BIOS, ill take a look at it and see if i can make that default clock speed +5mhz what it already is.
Make sure you have a spare PCI card to reflash back though if there is an issue.

[Max Tractor]

nibitor might be worth a shot, v2.9 is supposed to support 7900

[jimborae]

nibitor might be worth a shot, v2.9 is supposed to support 7900

I'll have ago then over the weekend.

[scrandman]

One more update: Just got another message from the XFX support guys.

Evidently the PV-T71G-UCE7 & PV-T71G-UCER are one and the same. The last letter refers to the packaging only. Therefore, this fix should work on both models.

[cpuchimp]

Hope it does.