While I know you need thermal grease between the heatsink base and the cpu silicon wafer, does it improve cooling performance if you use thermal grease between the heatsink base and the copper shim/spacer?
What about between the shim and the ceramic base of the cpu?
In theory, eliminating the air gaps should improve efficiency.
Has anybody seen any articles/ benchmarks?

In theory, yeah, it would. But, in practice, I believe (though I have no testing to back me up) that the difference would be negligable. The reason is that, because of the direct contact of the die and the heatsink, little of the heat is being conducted through the ceramic base.

By eliminating the air gap between the sides of the die and the copper shim, heat would be conducted away from the side as well as the top of the die- surely this is worthwhile?

Everything I wanted to know -and then some http://www.overclockers.com/tips278/

That link to the truth on the spacer will save me money.

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You still need a spacer to protect the CPU- just don't expect it to improve your cooling(unless you have a peltier...)

Agreed! Not much cooling effect, but some cheap insurance for your CPU. Especially if you are using a fop38 (damn clip)!

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