Actually, U6 is quite light weight... Previously I worry that the water block itself will crack the card due to its weight. But luckily 8800gts used 2 slots, so I managed to mount it firmly without any hassle by disperse the weight on those 2 screws.

that's the problem...i couldnt find the problem ...no air buble, the water flow is very clean n smooth...
anyway, running Q6600 G0 at 3.5G wif 1.38v, what do u think the acceptable temp?

ya lor...but mine load wif 71c...since i've use the same proc on hsf last time, it is logical for me to expect better temp wif WC, dun u think so and can u imagine that at idle it was 44c, load 71c (3.6G@1.45v). it was 27c different.
using hsf - geminiII & xigmatek, highest temp is around that la...71c but normally lower.

anyway, now i know that the problem is the contact between my proc and the cpu block. no matter how i mount it, it will produced the same result. my next probable option is to bow the GT, so hopefully can get better contact and better temp.