Lag in T2

Hey T2 players! It's me Uncle Blak with another T2 gem!

If you have lag issues that come and go more than should be expected AND you also have a newer system that uses the HPET timer and an OS that is HPET aware you may be suffering from lag created by the HPET system timer.

Here you can learn about HPET
http://en.wikipedia.org/wiki/High_Precision_Event_Timer

At issue with this new and improved system timer is that it uses an interrupt rather than a register in the cpu. The register in the cpu is much faster but not as precise, so you trade precision with variable lag produced by interrupts via HPET for a smoother but less precise system timer. In some systems you may have a much more responsive game by running the standard system event timer than HPET.

To stop using the HPET timer one must edit boot.ini in the root folder of your os drive, typically C:

http://support.microsoft.com/kb/289022

http://support.microsoft.com/kb/833721

Open boot.ini and place this line

/usepmtimer


so boot.ini looks something like this:

multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional" /fastdetect
/usepmtimer

then save and reboot

My core2duo based system runs much smoother in T2 with the standard pmtimer as opposed to the HPET timer.

If your system no longer boots after this editing don't blame me, do this at your own peril!

Comments

  • If you make the switch from HPET to standard timer you should also disable HPET in bios, if that option is present.
  • I would highly recommend not using this procedure. RTDSC tick count is frequently going to drift away from real time on CPUs with dynamic clock scaling through power management, and on multi-core or CPU machines will frequently have a different tick count for each execution unit.

    If you are having trouble with the game's default use of RTDSC, lock it to one core, or switch it to the HPET mode with the setPerfCounterEnable() console command.

    Disabling HPET on your system is about the worst way to deal with this problem ever.
  • If you want reduced responsiveness in game, use the HPET timer. If you want immediate response in game use pmtimer.
  • Never touch a running system...
    ::)
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