X1900XT vmem drop to 1.785?

[cadaveca]

SO, found the problem with overclocknig my x1900xt...
MVDDC drops to 1.785 ...


Ideas? no temp spikes or anything else weird at the time it drops.

[cantankerous]

how did you find out it is actually dropping? The only monitoring problem I know for realtime voltage changes is Rivatuner but as far as I know the latest build doesn't support X1900 cards.

[Chr0n1c]

I assume he monitored it with a DMM.....althought idk how or where you could get that off the card personally.

[G H Z]

Maybe a hot 5V line.

[cadaveca]

5v looks fine. 12v dipped to 11.84v from 12.03. Swapped out PSU and am retesting, but that's it.

Using stuff in sig, ocz 520w. Now on enermax 565w. Maybe this why the ASUS top cards have external power source.

Hmm.

OCZ only on vid? heh.

[G H Z]

By hot I mean around 5.5V

[cadaveca]

I know. 5v varies from 5.01-5.04.

starts happening around 750, and is very quick to drop @ 765.

Now here's the full story...

card new, did (in CCC) 690gpu, 729mem only. Upon checking contact, i found that the shround/ram cover heatsink deflected the board by abt 8 degrees. I pulled the ZAlman FS-V7 off the wife's XL almost immediately, and mounted it up. The stock heatsink started pulling the pcb down @ the power end of the GPU, with the screws between the GPU heatsink on that side and the screws for the shroud causing the deflection, or so i thought.

So now i'm checking for loose components.

lol.
anyway, obviously i'm @ 760 benchable, 747/24/7. I did get the same results after trying the stock heatsink again, after tightening the screws on the gpu heatsink that attach it to the shroud, as it was the heatsink sticking out a bit that caused the deflection in the first place.

Now I'm back @ stock, monitoring again, to see if i can catch it happening. the way the screen artifacts now, but continues to run, is the same as before i noticed the warped pcb, and I'm just using CCC to overclock so far.

[cantankerous]

my PCB bends towards the back as well. Noticed it right away when installing. My X1800XT never did this even though it has the same heavy cooler on it.

[cadaveca]

Someone else here had a bent pcb too, on thier watercooled card, i think.