Hi,
after two days of happily water-cooling my Sapphire 5970, problems started after a reboot. NO POST!
Absolutely nothing.
A few hours on the net, suggested two possible problems, either to hot on some components ... or two cold all together ...
Anyway, put back stock cooler, and guess what. No problems ...
Tried the water-cooler again, NO POST.
So I am clueless. Does anybody else experience similar problems. This is the first time I have trouble when watercooling GPUs, and I have tried some (2900XT, 3870, 4870X2 and 4890)
What is the problem?
Any hints is highly appreciated. Hopefully Catalyst 10.1 will solve the problem.
drbo
EDIT: And I am not alone ...
http://www.xtremesystems.org/forums/showthread.php?t=241616

Some hours of google, and it seem that my problems is now solved. Although I must admit that I do not really understand why (as many others)...
But is does seem that the 5970 (from all producers), has a coldbug at +35C, or so many suggest (that makes trouble when WC). YES you read the right number.
With the stock cooler, this is not a problem, since the card becomes hotter than a toaster in secods ... but on water ...
So my solution that works, was a combination of a new driver (found the Catalyst 10.1 RC2) and a custom profile, increasing the lower frequencies from 158 to 300, and the lower mem from 300 to 900. The driver is more stable, and the increase in minimum frequencies makes the card hot enough to boot
But the whole issue is strange, and the solution was not very obvious ....
drbo