Building a new workstation - dual or quad-core CPU for FreeBSD 7?

[Kris Kennaway]

Josh Carroll wrote:
>> In general, if you are running a multi-process or multi-threaded
>> workload, FreeBSD 7 will be able to make good use of 8 CPU cores.
>>
>> Over the past 2 years we have done extensive benchmarking and
>> optimizations that have resulted in *huge* performance improvements on
>> many common workloads on 8-core systems.  FreeBSD 7 is now regularly
>> outperforming Linux on the workloads we have compared.  In the near
>> future we will be widening our scope to 16 core systems as well as
>> investigating more benchmarks as we find them.
> 
> Isn't the default scheduler still 4BSD on -CURRENT? Is ULE considered
> stable on SMP systems now, and does it really outperform 4BSD? If so,
> will it be set as the default scheduler once 7.0 is released?

Yes, 4BSD is still the default, although you definitely want to use ULE 
for performance reasons (NB: only on 7, dont use ULE on 6).  I don't 
know whether the release engineers plan to change that default, but I 
will check.

> The P965 chipset boards will support the Q6600 and many of them will
> support Penryn when it comes out (the 45nm based true quad core Intel
> CPU). I have an Asus P5B and a Q6600 running at 3.4 GHz on 6.2-RELEASE
> and it screams (8:20 to build world with make -j8, for example). So
> even 6.2 will take good advantage of the 4 cores, and I imagine it'll
> only get better when 7.0 is released. I'd just avoid the bleeding edge
> motherboards/chipsets.

JFYI, buildworld is a really bad benchmark for testing SMP performance 
in general (on 4 cpus it is not too bad), because the makefiles are not 
written to efficiently parallelize builds on many CPUs, so large parts 
end up running with only a single make job at a time.

Kris