Windows Clock Resolution

BingoTheClowno · Post by **BingoTheClowno** » Thu Feb 17, 2005 5:25 pm

I think I mention this before, I just want to add some more info on this topic because I think this setting could be of relevance for audio systems. See this link for an explanation:
http://www.sysinternals.com/ntw2k/info/timer.shtml

This can be changed in the boot.ini (which is read only) file by adding the /TIMERES option, for example:
"multi(0)disk(0)rdisk(0)partition(1)WINDOWS = "Ms Win XP Home" /sos /fastdetect /TIMERES=21000"

(the /sos flag will cause the system to display drivers loading during boot-up)

/TIMERES=
Sets the resolution of the system timer on the standard x86 multiprocessor HAL (Halmps.dll). The argument is a number interpreted in hundreds of nanoseconds, but the rate is set to the closest resolution the HAL supports that isn't larger than the one requested. The HAL supports the following resolutions:

Hundreds of nanoseconds Milliseconds (ms)
9766 0.98
19532 2.00
39063 3.90
78125 7.80

The default resolution is 7.8 ms. The system timer resolution affects the resolution of waitable timers. Example: /TIMERES=21000 would set the timer to a resolution of 2.0 ms.

I found out that this switch doesn't work on ACPI enabled systems.

[ This Message was edited by: BingoTheClowno on 2005-02-17 18:17 ]

Micha · Post by **Micha** » Mon Feb 21, 2005 11:15 am

Careful, the information is good old NT 3.51/4.0. Have a look for XP etc. at
http://www.danisoft.com/services/Boot.INI_Reference.jsp
So I think that you cannot use this option to speed up or have more accurate timing by setting higher resolution, but you can get your 2 or more processors to coexist more smoothly.

[ This Message was edited by: Micha on 2005-02-21 11:31 ]

BingoTheClowno · Post by **BingoTheClowno** » Mon Feb 21, 2005 12:12 pm

It works with Windows 2003 Server. I have tested it at home. However, it looks like it only works on multiprocessor kernels (halmps.dll).

[ This Message was edited by: BingoTheClowno on 2005-02-21 12:13 ]

Micha · Post by **Micha** » Tue Feb 22, 2005 5:18 am

yes, it's just a balance thing between the one timer (hardware) unit and the two or more processors. Very helpful in case you need it. Thank you

I found this in the Library:
http://msdn.microsoft.com/library/defau ... header.asp
So it seems to be a parameter set by the hardware. Thus no tweaking possible, sad, but a great idea to check that out. You never know...
Thanks again.