BW wrote:

I bought a packet of Antec thermal grease yesterday to replace the
almost three year old pad between the processor and the heat sink. I
applied it on the processor+heatsink assembly and the machine is up now.
However, my system logs do not show any difference between the
temperatures with the thermal pad and now with the grease.

So there were a few doubts about the thermal grease which I used. The
consistency of the grease is similar to a 10% cream. But in the images
on the internet describing the process I had seen the grease to have a
consistency similar to that of a toothpaste.

Grease usually works better than a thermal pad because it usually forms
a thinner layer, but some thermal grease is so viscous that it's hard
to make it thin out, and you have to swirl the heatsink around while
pressing down or even warm the heatsink with a hair dryer (the
heatsink, not the CPU). Radio Shack "transistor heatsink grease" or
dielectric grease sold at auto parts stores (used for waterproofing
spark plug connections and cooling ignition modules) is perfectly
adequate.

Don't obsess about CPU temperature as long as it's cool enough, usually
70C or less for a modern CPU with a maximum temperature rating of
85-90C. 50C is very cool for silicon and there's no benefit in going
lower.