mysql and system/nice cpu usage

[TM4525 at aol.com]

In a message dated 10/31/04 11:03:12 AM Eastern Standard Time, 
ofsen at enderunix.org writes:
>but never come across with a problem like that. I am thinking to use Zend 
>Optimizer. Maybe that helps me .. 
>
>If that doesn't help I was thinking to run sql on a seperate machine. 

You might try tuning kern.vm.kmem.size if thats not in the tuning suggestions.
The OS tends to allocate way more memory than needed for the kernel if 
you have a lot of memory in the system; you probably don't need more than
100M or so unless you're running bgp or something unusual. Once you start 
swapping with mysql and php you're dead.

Moving to another system can help, but be aware that if your network is
busy it can add some "different" inefficiencies. If you do go to a separate
system connect it with a dedicated NIC if possible, to alleviate network
backup. If you have a multiple bus machine, moving your NIC to a separate
bus from the HDD can significantly increase performance. When you have
the NIC and HDD on the same bus, heavy network traffic can cause disk
operations to back up and substantially slow database applications. Make
sure the busses are really separate (and not cascaded), otherwise it won't
help.

Also if you're on a 32bit bus machine you'll have a lot more contention than
with a pci-x bus. Most people think that if you have enough bus then it 
doesnt matter, but thats dead wrong. Bus contention between devices is 
a major performance factor.