FBSD 5.x CPU performance on MSVS 2005

Tamouh H. hakmi at rogers.com
Sun May 21 20:55:47 UTC 2006


I've been doing some testing with Microsoft Virtual Server 2005 R2 and FreeBSD, so far compatibility has been great across the board with all versions of FreeBSD from 4.x - 7.x on IDE based virtual drives (no compatibility with SCSI driver).

However, on FreeBSD 5.x I noticed the CPU detected by FreeBSD is half of the actual CPU available (e.g. the machine has 6 x 900MHz CPUs and each VM is assigned a 900MHz CPU), yes FreeBSD 5.x detects the CPU frequency at 400-498MHz no matter what settings I try to change and what options I've added to the kernel. This usually resulted in "time went backward" errors and significant performance impact.

I tried FBSD 7.x-CURRENT and the CPU was detected perfectly fine as P-III 900MHz and performance was much better improved. 

Results were obtained through:

> sysctl hw.clockrate

I've left notes on this matter at freebsd-questions:

Any advise or check on this is appreciated, I can provide access to the VM machines if wanted.


Tamouh Hakmi

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