I happened to stumble on this (kinda old) page where the author is comparing Rails to Groovy performance. I was reading his comments, he was generally concluding that Groovy is faster than Rails. I didn't look at the graphs until I saw his comment that 10 Mongrels behind pound was much slower than a single Mongrel!!. I double checked the graph and this was the case! The 10 Mongrel setup is much slower in all the cases than a 1 Mongrel instance.

I was wondering where is the catch. Rereading the article I spotted it with little effort. Here's a ponder-this for those who read this blog (both of you), what did the guy do to screw up the performance figures that bad? If you get it, please add a comment with your answer.

Given his numbers, an appropriate Rails setup will make Rails suddenly faster (I don't mean any magic tricks, just fixing his fatal mistake). But the difference will not be that big anyway.

Update: seemingly no one discovered (or cared to discover?) the mistake, so here it goes. The lad used 10 Mongrels on a 1GB Ram machine that also ran mysql, OS X and whatever else he got running, he simply ran out of memory and started swapping. The numbers for the 10 Mongrel setup were including the disk swapping penalty. Couldn't he just listen to his drive or see a blinking led?