performance degradation in 6.2 when adding a second quad core chip

Kris Kennaway kris at
Fri Feb 22 19:09:12 UTC 2008

Noisex wrote:
> So Benjamin you want to tell, that adding additional CPU decrease the
> performance on 6.2? How did you made tests? 
> 	I just want to know because in my plans to the next week is also add
> 2nd CPU (dual core) and some additional RAM to one of the my HP Proliant
> DL360 (generaly mysql db server) because due to heavy MySQL usage nearly to
> 100% or even more sometimes some of my customers are not very happy with
> service like that (long load time).
> Server: HP proliant G4P DL360, CPU 1x3Ghz dual core, RAM: 4Gb (on system i
> can see 3Gb :) ), SCSI 146Gbx2 (RAID 1+0 with smartarray controller p4600).
> OS: FreeBSD 6.2, SMP

I wouldn't bother with 8 CPUs if you are running 6.x.  As I mentioned, 
7.0 SMP performance is much better.

> p.s what you guys could recommend about enabled/disabled hyperthreading on
> intel? Will it increase performance or over the left decrease?

It depends on your workload, it may or may not give a performance 
benefit.  ULE tends to perform better than 4BSD though.


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