All about timing
There really aren't many reasons to disable the HPET and a lot of good reasons not to.
If you're really interested in that goes on under the covers, have a read of this (warning it's pretty technical).
The short 'n simple version is that although a thread can query the time at relatively high accuracy, the shortest period of time it can release context and wait is controlled by the hardware interrupt frequency. For most systems without an HPET, this is on the order of ~15ms (huge oversimplification).
Having an HPET (or even better, an invariant TSC [Timestamp counter]) increases that frequency from the millisecond range to the microsecond range. TSC and HPET tend to be less susceptible to thermal drift too, meaning more consistent interrupts.
The factors controlling interrupt frequency are many and varied - from the OS version, through motherboard, CPU and BIOS support so my limited explanation above glosses over a lot of detail.
Hope that helps and apologies if adding a definitive resource is seen as necroing...
There really aren't many reasons to disable the HPET and a lot of good reasons not to.
If you're really interested in that goes on under the covers, have a read of this (warning it's pretty technical).
The short 'n simple version is that although a thread can query the time at relatively high accuracy, the shortest period of time it can release context and wait is controlled by the hardware interrupt frequency. For most systems without an HPET, this is on the order of ~15ms (huge oversimplification).
Having an HPET (or even better, an invariant TSC [Timestamp counter]) increases that frequency from the millisecond range to the microsecond range. TSC and HPET tend to be less susceptible to thermal drift too, meaning more consistent interrupts.
The factors controlling interrupt frequency are many and varied - from the OS version, through motherboard, CPU and BIOS support so my limited explanation above glosses over a lot of detail.
Hope that helps and apologies if adding a definitive resource is seen as necroing...