Stability of RELENG_5_4 with dual Xeon

[Lucas Holt]

Andrew McNaughton wrote:

>
> I'd be interested to hear people's recent experiences with Dual Xeons 
> under load with SMP on and HTT off.
>
> A while back there were stability problems with Dual Xeon machines.  
> I've got one of these in production with SMP turned off for the time 
> being.  I figure at some point things are stable enough to enable the 
> extra processor safely, but I don't have a spare machine for testing 
> safely.
>
> I gather there are still problems with Dual Xeon with both SMP and HTT 
> turned on, but that turning HTT off helps.  So the question is how 
> stable is that configuration?
>
> Andrew McNaughton
>
>
Aside from occasional problems booting the kernel, I've never had any 
problems with FreeBSD 5.3 or 5 Stable (a month before 5.4 release) using 
SMP.  The only problem was a timing issue starting the second cpu which 
would cause a kernel panic.  It usually only occured when rebooting from 
another OS.  I have a Dell Precision 650 dual xeon 2.0 ghz with HTT 
disabled.  Performance seems a tad bit better since upgrading to the 
stable version.  I'm in the process of building 5.4 release now. 

On a server, its probably good to have HTT off due to the recent 
security advisory.  Its off on my workstation simply because it seemed 
to slow down the machine in FreeBSD, Linux and Windows.