Hey guys, I did a simple test to find out the CPU/Core temperature at different water temp.

Test setups:

i7 960 4GHz, 1.32V, IHS removed and polished silicon die
xspc rasa water block, polished to 1500 grit
D5 pump on setting 5
ice...

I added ice to the pot and then let the water temp raise, and kept recording the temps.

Conclusion: the thermal resistance between cpu die and water block plays a significant role when the cpu is stressed. Due to the large amount of heat dissipating through small die-block contact area, the resistance is big. It results in 53C core temp with 20C water, even it's direct die cooling...