Why is MySQL nearly twice as fast on Linux/AMD64 Vs. FreeBSD/AMD64?

[Andrew Gallatin]

JG writes:

 > The benchmarks were done from a remote server on the LAN, using myBench.
 > Unfortunately, myBench doesn't seem to simulate actual real-world user loads.
 > Super-smack does, but I ran into problems compiling it, and then more when 
 > trying
 > to use it remotely. Super-smack-1.3 is supposed to be coming out soon, 
 > hopefully
 > it will fix some of these problems.
 > 

Can you describe in more detail the network configuration?  Is it a
gigabit link?

If so, have you compared just the network performance between FreeBSD
and Linux on this box, using the host you're running myBench on?  Try
the netperf port..

A recent posting in -net suggests there may be some network
performance problems on amd64 (or it could have just been the tester's
machine). (http://lists.FreeBSD.org/pipermail/freebsd-net/2004-May/004034.html)

Drew