High Precision Event Timer

[CrazyNutz]

HPET is High Precision Event Timer. It's exactly that..
It can be used by software or the os for very accurate timing, however when it's "ON/Enabled" then windows will use it as the main clock source instead of the other options like the cpu TSC (time stamp counter).

The HPET can provide more precise timing, however the OS has to reference it via a memory address, or I think the HPET can raise a interrupt,
so therefore it's slower.

The TSC may be less precise, however it's a register in the CPU so this is the fastest possible way to access a clock source.