Heat Problems with Athlon

[deadkenny]

I have an AXIA "9" T-Bird 1.2GHz which will run it's default speed with 1.525V (according to Bios, according to VIA HWM it's 1.54V) very stable and pretty cold at about 37°C. #When I overclock it to 1.4GHz it will need a higher voltage (yet runs with less than the default of 1.75V) but when I boot with higher speeds (1466MHz or 1533MHz or anything between) I have to rise the voltage to very high levels and my system will crash after a while (most likely because it get's to hot - the temperature is always rising with those speeds).
Could it just be a cooling problem? I'm usin a water cooling system that allows me to adjust the preassure between the cpu and the heat sink with a little screw. I fear to screw my system if I make more preassure. I still use no heat conductive paste or one of those Athlon CU Spacers - could those help me?

Thanks a lot...

 

[morriswindgate]

Put some Thermal Paste on it, the reason for this stuff is to insure that all the cpu area is in contact and conducting heat. Ceramic (what your chip is made of) is a poor conductor of heat because it has microscopic pits all over it that do not contact the metals of the sink or metal of cooling system. The paste fills in these hole and allows the heat to trave from the chip.

 

[PentiumIV]

<< Put some Thermal Paste on it, the reason for this stuff is to insure that all the cpu area is in contact and conducting heat. Ceramic (what your chip is made of) is a poor conductor of heat because it has microscopic pits all over it that do not contact the metals of the sink or metal of cooling system. The paste fills in these hole and allows the heat to trave from the chip. >>



This explanation is not entirely correct(for the Athlon/Pentum 3 case).
First of all, Athlon consists of bare die bonded to creamic substrate with pins.
(C4 bonding). The creamics is a relatively poor heat conductor, so the die is not entirely enclosed in ceramics. For Pentium4 there is an upper metal cover (Integrated Heat Spreader) over the die. This is done in order to improve heat transfer from the die to the cooler. By applying thermal paste between the die and the radiator you reduce thermal resistance between the die and the radiator, thus improving cooling.


P.S. Some thermal pastes are conductive, so you should apply them ONLY to the die. You may damage the CPU otherwise !

P.P.S. Most dielectrics (ceramics including) are poor heat conductors regardless of
microscopic pits