Overclocking/Underclocking Video Cards

On the topic of overclocking the 6800 GT, anyone out there ever heard of support staff actually being able to test a card to see if its core clock has been changed by software (coolbits registry hack)?

Without identifying myself I said I had underclocked my BFG 6800 GT after having heating issues. Not only does the supposed 'supervisor' ("I'm the highest person you can talk to in this company." ) say that it's possible it was damaged by underclocking it to the nVidia reference design clock frequency (350/1000) from the BFG overclocked default of 370/1000 but he also says that if it's sent in they'll detect that the core speed has been changed and simply send it back.

All of my technical experience says he's Full of S... on both counts, but I figured I'd ask around and see what everyone else says. I'll close with another great quote from this 'supervisor.' "Basically you have a $400 dollar paper weight." BFG's professionalism knows no bounds.<P ID="edit"><FONT SIZE=-1><EM>Edited by ahowell2k on 12/24/04 02:04 AM.</EM></FONT></P>

He's partially full of sh|t.
1) He (or the company) won't know if you changed the clock as long as the BIOS is the same and there isn't physical damage from an OC.
2) Underclocking from BFG to nV clocks won't harm the card (don't know why you'd do it, other than as a 2D setting). HOWEVER, underclocking to 250/800 (or so, pretty much any extreme UC) likely WILL cause damage!!! This may seem bogus, but there really is a range of clocks that a card can run in, and it's not 0 - ###, more like *** - ###. For some reason(s), (I think the memory and the core, but maybe just the memory) can't go below a certain clock before it will start to cause equally damaging graphical corruption.

However, this might not be true with 6800s, I can only confirm it on a GeForce 2 GTS; a Gefore Ti 4200, 4400, 4600; and all Radeons from 9500 to X850. I'm really not sure about lower model ATis or the past two generations of nV cards--but I haven't seen a card that DIDN'T artifact and crash at heavily reduced clocks!

As for your overheating issue, RMA it--no reason to have a bum card.

Maxtor disgraces the six letters that make Matrox.