In the following overclocking test with the
phase change cooling installed, we found the Pentium 4 2.4C wasn't the
limiting factor, it was the motherboard. In the end, the highest
I was able to overclock the 2.4 GHz processor was 4.08 GHz, while maintaining 100% stability.
Unfortunately, anything higher and the motherboard's northbridge would start to generate Prime95 errors.
According to SiSoft Sandra, the Pentium
2.4C CPU running at 4.08 GHz with a voltage of 1.75V produces around 120W-130W of
heat. That's a significant amount, but who cares when your CPU idle temperature is -40 Celsius.
With load, that temperature hovers around the -32 degrees Celsius mark!
For those of us who like our computers
silent, or at least very low noise, it is worthwhile to mention that phase change coolers are in general very quiet. In the unit
we used for these experiments, there is only a low pitch hum from the compressor. The 120mm fans
spin at a low RPM and are almost inaudible.
While Phase change cooling sounds pretty
complex next to a simple heatsink and fan, there are
even more exotic forms of cooling available. Techniques such as cascade phase change cooling,
dry ice and even Liquid nitrogen have been used at one time or another. They
are not viable commercially, and present some serious safety issues as well.