Thermal compound coverage

[odie072]

I'll hopefully be receiving my replacement CPU today (p4 3.0E Prescott), and new heatsink. When I pulled my old CPU and heatsink apart, the thermal paste I applied last time (AS5, rice grain size and twisted heatsink to spread), only covered about 1/3rd of the CPU. Is that OK or should the compound cover most of the CPU? I've been reading that the Prescott runs pretty hot, so I want to make sure it cools ok. The new heatsink is a Zalman 9500A and the case has 7 fans.

Thanks
odie072

 

[Alvin.C]

Hello,

This is alright for a processor like yours.

On a processor with an exposed die, you'll want a thin even layer across the entire die of the CPU. I apply a small amount of thermal compound to the CPU die, and use a small piece of plastic card to spread it evenly across the surface...

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On a processor with an integrated heat spreader (such as your processor), you'll want to apply a small amount to the centre of the integrated heat spreader of the processor, and just let the pressure of the heatsink spread it around. The following image illustrates the distribution of the thermal compound after the heatsink has been installed and removed...