Unix - Hardware Timer Selection

• To find the timer counter being used by the computer:
  
  myhost# sysctl kern.timecounter.hardware
  kern.timecounter.hardware: HPET



• List of available timers:
  
  myhost# sysctl kern.timecounter.choice
  kern.timecounter.choice: TSC(-100) HPET(900)

The integer value within brackets defines the quality of the time counter compared to others. A negative value means this time counter is broken and should not be used.



• Selecting the timer of your choice:
  myhost# sysctl kern.timecounter.hardware=TSC
  
  Note: This selection does not persist after a reboot. To make this change persistent add the following line to the file /etc/sysctl.conf:
  sysctl kern.timecounter.hardware=HPET