Platform
Apache 1.3
2GB Ram
PHP 4.4
GZIP compression

Same Page uses Smarty and a bunch of includes and file reads.

Without any type of caching the server worked at about 31/32ms
With eaccelerator 15/16ms (after initial 32ms hit)
With PHPExpress 15/16ms (after initial 32ms hit)
ZendOptimizer 15/16ms(after initial 32ms hit)


So performance wise I don't see much of a difference when they work. But then again it is a little subjective.

Leigh

Did you use Apache's ab for the benchmark tests?
Did you try heavy-sized php scripts running alone? Did you try small scripts with large number of included small files?

I was just using a Cpanel 11 Install of apache. My test used a Firefox plugin called Firebug which can show network times for files (so in the at 13MS there is some network time.

Granted I Probably could get some more detailed stats I find these are a bit more 'real-world' It DOES split apart each HTTP request So you can actually see

The scripts do some includes, directory scans, database calls, file reads and writes. Bascially a LOT of db calls and using smarty to do display (Smarty is called several times)

It has about 25 PHP Files most under 1K but some up to 25KB

Personally I'm VERY PLEASED it was a drop-in install and I could see a difference even with running DBG...