CPUTYPE in general - was Re: Which CPUTYPE for a dualcore Xeon on AMD64

[Martin Turgeon]

Mike Meyer a écrit :
> In <20070625192308.GA14544 at freebsd.org>, Roman Divacky <rdivacky at freebsd.org> typed:
>   
>> you should know what cpu you bought, or just use cpuid (found in ports)
>> and determine what cpu you have.
>>     
>
> Knowing what CPU you bought doesn't help a lot for the case asked
> about of "nocona" vs. "prescott". Those are the names of P4 and Xeon
> cores, not CPUs - and not the last cores used in either line. cpuid
> will tell you what features your CPU supports, but not the name of the
> core. So it only helps if you know what you're looking for. P4 and
> Xeon are just marketing names, and the features available vary quite a
> bit across the lines. Even knowing the core names doesn't help, as
> some prescott cored P4s have all the gcc "nocona" features.
>
> Assuming the gcc man page is correct, use cpuid to check the feature
> sets of your CPU. If you don't have SSE2, then you should be using
> something prior to pentium 4. If you have SSE2 but not SSE3, then you
> want pentium-m, pentium4 or pentium4m. If you have SSE3, then you
> should be using either nocona or prescott. If you have 64 bit support,
> you want nocona, otherwise prescott.
>
> For the record, I believe the nocona cores are:
> pentium 4/some prescott, prescott 2m, cedar mill
> pentium D/all
> core 2 duo/all
> All xeons with sse3 except the sossaman cored Xeon LV.
>
> The prescott cores are:
> pentium 4/some prescott
> xeon lv (sossaman core)
> core solo
> core duo 
>
> 	<mike
>   
Thanks a lot for the precision, I will use nocona for my dual core Xeon.

Martin