Re: Multiprocessor

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From: Marin Marinov (mlmarinov_at_askme.ca)
Date: 05/21/04 

Date: Fri, 21 May 2004 15:26:42 -0400

<snip>
It will use all of the 4 CPUs eventually but it cannot use more than 2
at a time since you have only 2 threads. Which 2 CPUs exactly - you
can't predict. The next time the OS tries to run the thread on the same
CPU it last ran (the soft affinity I mentioned before) in order to
possibly make use of remained data in L2 cache. But again, this is not
guaranteed. Here are 2 great articles on the internal algorithms. Though
they are for NT 4.0, you'll get a pretty good idea of what goes on
behind the scenes:
"Inside the Scheduler"
http://www.winntmag.com/Articles/Index.cfm?IssueID=22&ArticleID=302
http://www.winntmag.com/Articles/Index.cfm?IssueID=23&ArticleID=303

So initially, yes, the application's threads will be dispatched to
different CPUs, you don't have to explicitly code anything to benefit
from the multiple CPUs except the multiple threads (which you have
already done ;). Also by default, the process's affinity mask is set to
"all processors" so here you don't have an issue either.

As for the OS, I'd go with Windows Server 2003. There have been quite
some kernel improvements and this OS really rocks! Doesn't matter which
"modification" you get (Standard,Enterprise,Datacenter) - they all have
the same kernel. I'd stay away from non-server OSs - I have found them
to be generally "slower", but that's a personal observation though there
are technical explanations also. And if you want to take resource
utilization things further and just to ignite your interest check out
"Windows System Resource Monitor" - one more reason to go Win2K3:
http://www.microsoft.com/windowsserver2003/downloads/wsrm.mspx

HTH 

-- 
Cheers,
   Marin Marinov
   MCT, MCSE 2003/2000/NT4.0,
   MCSE:Security 2003/2000, MCP+I
-
This posting is provided "AS IS" with no warranties, and confers no 
rights.

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