Feb 14, 2006

Firstly i will start with my hardware and software:

CPU: Dual Xeon 3200 FU
Motherboard: Intel SE7520JR2ATAD2
OS: Windows XP pro SP2 (Also tried Windows 2003 server, x64 editions of XP/2003, even tried beta version of Vista/longhorn) but the problem is still the same. (something about NT core?)
Program: HLDS ( Half Life Dedicated Server (using sys_ticrate 10000 (limit number of updates))).
Drivers: I am using all latest drivers, system updates and firmware.

First of all i dont really know how to explain it technicaly, the thing i will talk about is called Windows Multimedia timer / system timer / sleep time. I am not sure about correct name, but you will understand it from my future words, at least i hope so.
By default this timer is running on Windows systems with 16ms delay, when im running my HLDS i am getting 64updates per second, and it addes around 16ms in ping, i noticed that if i start media player with paused movie in same time, i will get 512updates and around 3ms delay. That means that Windows Media player making this timer lower. But its only 512updates, while limit of HLDS is 1000. I was looking for a solution for a long time and finally found! I changed ACPI driver to ACPI PC and yes! I got 100fps by default (~5ms delay) and 1000fps and zero delay with Media Player on! It was working perfect on my home PC with only 1 CPU. On my server with Dual Xeon it was working also but... But it seems that only 1 CPU was working, ACPI PC isnt that good for Multiprossesor system, i lost a lot of hardware power with it, so i changed it bacl to ACPI multiprocessor and having only 512updates on my server atm.
The question about my problem is:
How can i get 5ms delay or 0 delay with media player on, without losing any hardware resources(With normal ACPI multiprocessor driver). I remember it was good in old windows 9x times. (Maybe its possible to change timer over regedit or over some services or get some specific driver).

- on Linux systems this problem can be solved by changing kernel ticrate to 1000HZ.

I hope to hear a solution for getting zero delay on Windows system.
Thank you!


Apr 1, 2004
ACPI cannot be applied to older hardware; for it to work, the operating system, the motherboard chipset, and for some functions even the CPU need to be designed for it.