[Mediawiki-l] Windows Apache & IIS vs Linux Apache performance differences

[tthompson at envisionware.com]

We're using MediaWiki on our corporate Intranet with great results. It's
perfect even for a smaller company.

The configuration is as follows:
    MediaWiki (http://wikipedia.sf.net/): 1.4.4
    PHP (http://www.php.net/): 4.3.10 (apache2handler)
    MySQL (http://www.mysql.com/): 4.0.18-max-debug-log
    IIS 5.x
    Windows 2000 Server on 2Ghz Pentium 4, 512MB RAM, SCSI RAID array
    Also: Apache 2.0.52 for testing

This rather non-trivial server gets a 100% CPU spike for 2 to 5 seconds on
each page view in the wiki. Ugh!

Apache on that same server didn't give any noticable speed improvements.

Just on a whim, I installed the same MediaWiki code on a Linux laptop,
running PHP 4.3.10 and the same Apache version. It's querying the MySQL
database on the main server.

The Linux/PHP/Apache on the Pentium 3 850Mhz laptop with half the RAM is
nearly FOUR times faster! That's half the RAM, a third the CPU speed...
but it dusts Windows 2000.

I can bring up two browser windows, with the Windows wiki in one and the
Linux wiki in the other, and click "Random page" in both windows. I can
click thru 4 or 5 random pages in the Linux instance in the time the
Windows instance brings back one.

To get Windows performance like that, I had to run the PHP code on a dual
CPU P4 with 1GB RAM under Windows 2003 Server.

Are there any optimization options I could be missing? I've already
enabled page caching on the server (works well), installed the Zend
Optimizer (free version), and ensured that I'm not dealing with the
dreaded multi-redirect bug. The CPU hit on the Windows server is huge.
MySQL isn't breaking a sweat at all.