Also seeing 2 x quad-core system slower that 2 x dual core

Claus Guttesen kometen at
Fri Nov 30 07:21:16 PST 2007

> > Yes, if the claim is that the hardware is absolutely identical apart
> > from one having two quad-core CPUs instead of two dual-core, the next
> > step is to disable half of the CPUs and confirm that the problem goes away.
> Just comming back to this today, will do a side by side compare of the dmesg
> later to make sure that they *are* identical as claimed, but the idea of
> disabling half the CPU's is an excellent one!
> Aha, brilliant idea!
> > Check dmesg for the APIC numbers corresponding to the CPUs you want to
> > disable and add the corresponding entries to /boot/loader.conf, e.g.:
> You mean this bit?
> FreeBSD/SMP: Multiprocessor System Detected: 8 CPUs
>  cpu0 (BSP): APIC ID:  0
>  cpu1 (AP): APIC ID:  1
>  cpu2 (AP): APIC ID:  2
>  cpu3 (AP): APIC ID:  3
>  cpu4 (AP): APIC ID:  4
>  cpu5 (AP): APIC ID:  5
>  cpu6 (AP): APIC ID:  6
>  cpu7 (AP): APIC ID:  7

For completeness sake :-) you could try to disable the second
quad-core-cpu completely rather than 2 cores on each unit and redo the


When lenity and cruelty play for a kingdom,
the gentlest gamester is the soonest winner.


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