Anandtech pits G5 against Linux on x86

Johan De Gelas has pitted a G5 desktop against some high-powered x86 machines (two Xeons and an Opteron) in a no-holds-barred cagematch. Johan spends the first few pages detailing the minute differences between the processors in each machine down to the Branch History Tabls and Core Voltages and finally gets to the interesting stuff on page 6:

Ever heard about the famous English Plum pudding? That is the best way to describe the MySQL performance on the G5/ Mac OS X server combination. Performance is decent with one or two virtual client connecting. Once we go to 5 and 10 concurrent connections, the Apple plum pudding collapses. …

…The new OS, Tiger doesn’t help: the 2.7 GHz (10.4.1) is as fast as the 2.5 GHz on Panther (10.3). More importantly, Apache shows exactly the same picture as MySQL: performance is 10 times more worse than on the Xeon (and Opteron) on Linux. Apple is very proud about the Mac OS X Unix roots, but it seems that the typical Unix/Linux software isn’t too fond of Apple. Let us find out what happened!

It turns out that OS X really bites the big one when it comes to serving mySQL and Apache connections under high loads. Anandtech trys to explain why OS X seems to be so slow with some stuff about posix threads and mach threads which turns out is mostly bunk:

They claim that making a new thread is called "forking". No, it’s not. Calling fork() is forking, and fork() makes processes, not threads.

They claim that Mac OS X is slower at making threads by benchmarking fork() and exec()… Making a new process is substantially different from making a new thread, less so on Linux, but very much so on OS X. And, as you can see from their screenshot, there is one mySQL process with 60 threads; neither fork() nor exec() is being called here

They claim that OS X does not use kernel threads to implement user threads. But of course it does – see for yourself.

And so on. Do any of our readers put OS X machines into daily and heavy use as Web/DB machines alongside linux boxes? Do you notice such an obvious disparity? Can anyone come up with any additional plausible reasons why OS X would seem to have such a blatant disadvantage?