6800 Ultra Overclock

[-D-Cypher]

Ok, so i run my card at stock settings on 3d Mark and get 5000. When I overclock it to extreme speeds, i get 4000. Can someone tell me whats going on?

Do I need to flash my bios?

Also, what is the max temp i should go with the overclock.

And, is there a max recommended clock.

 

[legcramp]

it's heat/power issue..when you overclock your core too high..and it gets too hot...the card automatically lower the speeds thus giving you a lower score...

 

[-D-Cypher]

so i'm guessing the only way to fix it is to get better cooling?

 

[LordBritish]

Better cooling and more voltage - you have to do a BIOS flash for that.

There are at least 3 voltages.

* AGP
* GPU
* Memory

Increasing AGP voltage does virtualy nothing BTW. Set it no higher than 1.6v.

When cooling, you will have to be concerned with both GPU and memory cooling. Some video card coolers only cool the GPU.

One nasty trait with 6800 GT/Ultras is increased stuttering with overclocking. In some games like FarCry, my 6800 Ultra will start stuttering. This goes away when I decreae the overclock.

Basically add voltage, add cooling, then crank up the overclock.

Pay attention to both stuttering and artifacts.

My evga 6800U does 450/1.14 with stock cooling and modded BIOS to increase GPU voltage. I have no artifacts and no stuttering. If I go higher, I'll get stuttering in FarCry - that's a good test.

Good luck.

 

[-D-Cypher]

can i have more information on the bios flash?

Thanks guys.

 

[mulpsmebeauty]

You'll need to search these or other forums for more info on the actual flash process, but this link contains some BIOSes and explanations of what they do:

http://cssource.game-host.org/6800ubios/

 

[GregP24]

mvktech.net has a ton of BIOS's as well.

If you are on the stock heatsink, order eVGA's copper UEE heatsink and lap it(the finish it comes with is horrible) this will help keep your temps down and get a better OC. Or order an NV Silencer. You have to cut the backplate in half to run it, which is why I never used one.

My 6800U with a UEE BIOS would go to 470/1230 with no problems on 1.5v, at 1.4v I could only get 465.