MySQL performance concern

[Ronald Klop]

On Sat, 02 Oct 2010 09:06:52 +0200, Rumen Telbizov <telbizov at gmail.com>  
wrote:

> Hello everyone,
>
> I am experimenting with MySQL running on FreeBSD and comparing with  
> another
> (older) setup running on a Linux box.
> My results show that performance on Linux is significantly better than
> FreeBSD although the hardware is weaker.
> I'd appreciate your comments and ideas.
>
> Here's the setup:
>
> 1) FreeBSD 8.1-STABLE amd64 (Tue Sep 14 15:29:22 PDT 2010) running on a
> SuperMicro machine with 2 x Dual Core
> Xeon E5502 1.87Ghz ; 4 x SAS 15K in RAID10 setup under ZFS (two mirrored
> pairs) and 2 x SSD X25-E partitioned
> for: 8G for ZIL and the rest for L2ARC; 16G ram with 8 of them given to
> mysql and tons of free.
>
> 2) Linux Gentoo with 3 SATA disks in hardware RAID5 with similar
> cpu/motherboard and same memory size.
>
> The sole application that runs is a python script which inserts a batch  
> of
> lines at a time. Only myisam is used as a format.
> Here's the problem: On the Linux box it manages to push around
> *5800*inserts/second while on the FreeBSD box
> it's only *4000/*second.
>
> MySQL version is 5.1.51
>
> During this load the disk subsystem on FreeBSD is pretty much idle (both  
> the
> SSDs and the SAS disks). CPU utilization
> contributed to mysqld is only around 30%. So I am clearly heavily
> under-utilizing the hardware.
> Linuxthreads support for 64bit architectures is not available so I  
> couldn't
> try that but aside from that I tried recompiling
> mysql with all the different Makefile options available without any  
> effect.
> Changing the recordsize in zfs to 8K doesn't make any difference.
> Tried percona binary without any luck.
>
> Let me know what additional information would be useful and I'll provide  
> it
> here.
>
> Thank you in advance for your comments and suggestions.
>
> Cheers,
> Rumen Telbizov

Your app is singlethreaded I presume, so the multi-cores are not relevant  
in this story.
Do you have the same indexes on the tables on both servers?
Do they both have the same way to connect with mysql? Unix sockets or  
localhost?
Do they both run mysql 5.1.51, because you mention the Linux one is older?

Ronald.