Weird overclocking 6800GT.

I can overclock my card's core quite a bit before artifacts start appearing, in fact I don't start getting artifacts (as detected by ATI Tool/rthbl demo and my own eye) until the 450 range. My problem is that when clocked this high it will play a game or demo or anything I throw at it for between 1-30 minutes and then out of nowhere the entire screen turns into blocky artifacts. These aren't the memory type artifacts that I know from my old 9800 Pro (triangles etc.), the entire screen just fills up instantly with blocks of artifacts that look like plaid cloth.

With my 9800 Pro, I would get artifacts with textures with too high of a core and also water, and too high of memory I'd get wierd triangular spikes on the screen. With my 6800GT if I clock it high enough (core) I will get texture-like artifacts like on my 9800 Pro but only if I clock it far past the point that it goes to plaid. I was wondering what was causing my artifacts to appear in this manner, I've never had a graphics card that will completely turn a screen to artifacts instantly without showing any at all prior.

The card is watercooled and never gets over 55ish on full load so I don't think it's the core overheating. Memory clock doesn't seem to affect the whole screen artifacts either.

Any help would be appreciated. If nVidia cards artifact like this regularly and I just don't know about it that's news to me, but then again I've always been an ATI guy since the GeForce 3 so I wouldn't entirely know. Thanks for the help!

Derek.

well, it artifacts when it overheats, so it looks like its only artifacting under load, and when u stressed it, THEN it overheated

I thought it might be heat, but it's just so weird that there's no sign of artifacts for x minutes then the whole screen goes haywire. I might invest in some better cooling, because I've gotten some pretty awesome overclocks on this thing before it decides to artifact out on me.

hehe, good 4 u

What program are you using to oc your card?

Just coolbits and I manually look for artifacts.

Do you have it volt modded? My card did that when I had the bios set to1.4v in 3d.

It isn't volt modded, I had it volt modded in the past but brought it back to stock voltage after finding it didn't overclock much more.