Overclocking 7900

[westy87]

OK so ive tried to run the find max core option on atiTool a few times now and it just keeps going till it freezes up and restarts computer. What should i do?

Oh and what is the default mem speed for a normal xfx7900gt rather than my extreme version? Cause AtiTool gives a message that the overclocked mem could cause problems so figured id set mem to a stock 7900gt speed and try

[Bio-Hazard]

Just make note of where it freezes and then manually set the core slightly below that point and then check for artifacts........;)

[westy87]

Just make note of where it freezes and then manually set the core slightly below that point and then check for artifacts........;)

OK. also before it gets to point of freezing the lil spinning cube basically becomes unrecognizable. hang on ill screenshot it lol

[Bio-Hazard]

That telling you that the OC is full of artifacts, you need to back it off to a point where the cube is clean and then run the checker again.

[westy87]

Heres Screenshot

Can you explain why there are the 3 different clock speeds? 2d, 3d low power and 3d performance. What do i concentrate on?

[Bio-Hazard]

3d performance is what you need to worry about...........;)

[westy87]

Ye i thought as much. Do i need to do anything to the other 2 at all?

[Bio-Hazard]

I don't as it's plenty fat enough in Windows, but it's completely up to you. It'll just make things run hotter "ALL" the time.

[westy87]

Sweet Thanks. One last thing. What gives best performance improvement. OC the gpu mem or gpu core?

[Bio-Hazard]

Both......;) I get both as high as possible.......;)

[pc_man_iac]

Ye gettin both high, really helps, but w/e U can push it to do, I guess is ur thing

[werty316]

When you start seeing those dots, that means you should stop as those are artifacts.

Normal clock speeds for a 7900GT are 450/1320

['Amp!']

If you are using an aftermarket cooler try to do a VERY simple volt mod.

I volt modded my MSi 7900GT which came with a sight OC.
I couldn't add any more juice to the memory so I added some to the core (1.4v) and by doing so it actually let me OC my memory more. Go figure.

My 24/7 OC is
675 MHz Core
1800 MHz Mem.

[westy87]

Im just running the stock xfx7900gt cooler. Its the lil fan that covers the core and makes the ram fend for emselves. Im stuck at about 549 core and 1610 for memory before it starts artifacting. I usually run the artifact test for 5 mins. Max that ive seen the temp for it (using AtiTools temp reading) is 65 celcius and it says its about 47 celcius wen idle

[Bio-Hazard]

I wouldn't go volt modding the card if I were you, that is unless you can afford to replace it on your own after you void the warranty. I know that there are simple way to remove the mod and RMA the card, but people that do that sort of thing are just pretty much low lifes and do nothing but hurt all the others out in the world by driving up prices .

[Xero (1)ne]

I got my memory to 1.8Ghz easy with loosening the memory timings in the video card's bios using NiBiTor...I'm thinking about tightening them up again.

You can also modify the voltage tables, but I don't think it does much, because I think you can only go a tad bit higher without a voltmod.

['Amp!']

Only volt mod if you already have an aftermarket cooler. If you are getting artifacts at the cards stock settings then you should pick up an aftermarket cooler and if you have a multimeter test the voltages of the memory and core as they sound like they may already be volt modded by XFX.
http://forums.anandtech.com/messageview.cfm?catid=31&threadid=1847758

[westy87]

Ive overclocked to 549core (up from 520 stock) and from 750 up to 803 on mem. If i tried going higher on core i got artifacts and higher on the mem seemed to freeze my computer. Im happy there for now. I didn't really need the extra boost for UT24k and FEAR but it helps slightly in nwn2

[Xero (1)ne]

If anyone's daring enough, try tightening your timings using NiBitor.

It really helps, I used ATITool to monitor which settings were stable or not, and I didn't need to reboot to test them since NiBitor can change them on the fly! :mrgreen:

But the performance increase I saw for this was amazing, I went from about 610fps average to about 700fps average!!!!!!!

You guys might think this is a joke but I'm really not kidding!!

The only thing though is that I think i loosened my timings up a while ago, don't quite remember but I think it was a bit much when I was overclocking...(went from 34 to 0 on one of the timings, 25 to 0 on another)

Nevertheless, I would recomend to anyone to try it. If one timing turns out to be bad, just hit the reset button, and continue where you left off....:wink:

[werty316]

But the performance increase I saw for this was amazing, I went from about 610fps average to about 700fps average!!!!!!!
Were you playing Pong to get those kinds of frames? :biggrin:

[Xero (1)ne]

Har har,

No I that is from ATITool.