From: Heesob Park <phasis@...>
Date: 2008-10-15T17:36:02+09:00
Subject: Re: Multiple Processors on Windows 64-bit

2008/10/15 Bryan Richardson <btrichardson@gmail.com>:
> Hello all,
>
> Does anyone know if it's possible to force multiple Ruby applications to
> run on different processors?  I've got a dual quad-core machine that is
> running Windows XP 64-bit and I'd like to run multiple Ruby applications
> on it.  However, when running multiple applications, it looks like they
> are sharing the same processor -- one application will do some work for
> a while, then another one will, then another.  They aren't all doing
> work at the same time.
>
> Any ideas?!
>
On Windows 2003 or later, you can manually set CPU affinity using
start utility in the command prompt.

To start ruby process on CPU 0:

start /affinity 1 ruby some.rb


Affinity number is
1st core = 1
2nd core = 2
3rd core = 4
4th core = 8
5th core = 10 ( hexadecimal 16 )
6th core = 20 ( hexadecimal 32 )

You can also set CPU affinity with PsExec utiltiy.

Regards,

Park Heesob