> > Basically, I'm wondering:
> > (a) if the bus gets saturated with four CPUs
>
> you can saturate the bus easily by deliberately falling out of cache. I
indeed, lots of "compute-bound" apps are strictly dram-bound. for instance,
almost anything involving large matrices, physically-based simulations,
image processing, etc. and basically all x86 memory systems deliver
between 100 and 350 MB/s. a single Celeron/PII/Xeon on a BX board with
PC100 sdram will deliver the latter.
so the answer is that yes, even one mid-range CPU can easily saturate dram.
this is why SMP (which splits the 350 MB/s over multiple CPUs) makes no
sense for many apps.
> onestream_store : 11878919 cycles. (172.39 MB/sec)
> onestream_simple_load : 7683543 cycles. (266.52 MB/sec)
the Stream benchmarks are the standard here, and these numbers look a little
low.
> echo '- some SDRAM magic?'
> setpci -s 0:0.0 77.b=00
> ...
cool...
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