Re: [bgl-discuss] peak bandwidth

[Andrew Siegel <siegela@xxxxxxxxxxx>]

To be sure, you are certain that you are fitting entirely in L1-cache
(that's what the 11.2 assumes)? If so, I believe I can show you how to get
the rest, though I have to refresh my memory. Please confirm point 1
first, though ...

On Fri, 23 Sep 2005, hongzhang shan wrote:

> Hi,
>
>  I am testing STREAMS benchmark and Apex-Map benchmark on bluegene.
> Both codes meaasure the available bandwidth. I find that no matter how
> small
> data sets I use, or what data pattern I access, I could only get around
> 3GB/s/cpu
> bandwidth at most. This is only around 1/3 of 11.2GB/s peak.
>
>  The compiler option I used is : blrts_xlc -O4 -qarch=440. I am
> wondering whether
> I did not use the right option.
>
>   Also I am wondering whether somebody has play around with the memory
> bandwidth before
> on bluegene and get some good performance, such as over 5GB/s. If so,
> could you
> let me know ?
>
> Thanks a lot!
>
> shan
>
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