SMP on quad xeons

[Erich Dollansky]

Hi,

jromero at save-ferris.com wrote:
> Posted to freebsd-smp but didn't get too many replies, so I apologize for

I am on that list too but I can't remember your posting.

> cross posting ahead of time.  Need to configure groupware server and
> multiprotocol wireless proxy for aproximatly 2500 accounts. Application
> is heavily multi threaded and willrequire alot of CPU power. The OS will
> be FreeBSD 5.x Thinking of going with ServerWorks* Grand Champion HE quad
> xeon server board. Has anyone had any SMP experience with quad xeon

I read on the list several times that FreeBSD has problems when 6 or 
more CPUs are in a box. You could be affected by this if HTT is enabled.

There is currently a lot of development around the new scheduler (ULE) 
which will be usable very soon. Check the mailing list to find out more.

Another thing. Did you consider Opterons? Tyan has a board with four of 
them. You would not be affected by the 6-8 CPU 'problem'.

> systems on freebsd 5.x???  I'm curious to know if anyone experienced
> any major technical stumbling blocks. I guess I also want to know how
> well Freebsd 5.x will scale on a 4 proc. Will freeBSD 5.x utilize
> a quad xeon board as efficiently as linux2.6 system ??
> 
I cannot tell as I never used Linux.

I run FreeBSD on a Dual-Athlon with the old scheduler (BSD). My 
experience is that this scheduler is not as good as the one you find on 
Solaris or HP-UX. This is also the reason why the new one was developed.

Erich