Re: [eigen] Performance gap between gcc and msvc ?

[Rodney Sparapani <rsparapa@xxxxxxx>]

On 06/18/10 03:51 PM, Gael Guennebaud wrote:
> yes, that be very nice. Does anyone know to query the cache sizes? One
> solution would be to write some assembly to query the CPUID and then
> manage our own table but well I hope there exist something simpler!
>
> gael
>    
Hi Gael:

I don't know a portable way.  ATLAS has a tool to find the practical
limit of the L2 cache that you want to use based on performance.  You
need to do find it experimentally and then hard code that limit.

http://math-atlas.sourceforge.net/errata.html#tuneCE

Hope this helps.

--
Rodney Sparapani       Center for Patient Care and Outcomes Research
Sr. Biostatistician               http://www.mcw.edu/pcor
4 wheels good, 2 wheels better!   Medical College of Wisconsin (MCW)
WWLD?:  What Would Lombardi Do?   Milwaukee, WI, USA