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^800's Thermal throttling under cold conditions

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Dukemurmur

Member
Joined
Mar 13, 2004
Location
USA, Vermont
Like is stated is this a real big problem with these cards can it be fixed or what can be done...as I plain on using -40 deg or below chilled water to cool my system...and I have an NV-68...so that kinda limits my graphics card to a 6800...so I was wondering if there was ANY problems at low temps...and if there is can they be fixed

Any and ALL help would be great...
 
Dukemurmur said:
LOL sorry about the carrot it was supposed to be a 6 lol...but yeah any info on it...
Ill do my best to explain it:

From what I understand the 6800 does not understand - temps. Instead it sees it as a true value. If you are going to oh say -20 thats fine. The 6800 would treat it as 20* +.

However these guys on LN2s are -100c* which forces the card to start throttling as it registers it as 100C
 
to prevent throttling, mod the bios and set 3d low and high to the same voltage, and mod the 3d clocks to what you want it to run at, that way when it wants to throttle it gets fed the same voltage and you are already running at 'default' speeds
 
When do they start to throttle down? like at 65deg or even higher becasue i geuss that i should be good with -40 if that is the case in which they read all - values as + ones...
 
i believe it's below 22c where they "reset" and think that they're at the highest temperature and throttle. i've had good luck with playing around with my bios (2d and 3d speeds) so once I get these new rods for my pelt block I'm going to try my 6800u out with a 172w pelt.
 
Keep me informed...as I NEED to know because i have an NV-68 water block and chiller on it's way...and it will pull down the water to -40 or even below by the time I am done...I have heard tell that Asus cards don't suffer this problem? Something to do with the bios maybe...one thing that I was thinking is if there is a way to hard mod the card into thinking that it is say at 40deg ALL THE TIME so that no matter what it wont or can't throttle? I mean all it is, is a resistance or voltage that it receives from the probe I will talk to my teacher about it...

Does any one know where I can get my hands on a schematic of the 6800gt-ultra so that I can take a look at this...hard mod idea…then I just need to gather some info…if I can find out the test points and so on I guess that I will have some people on water, stock air, and aftermarket air see what they can find on the temp resistance or voltages…

Devin
 
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