Re: Minutes from 10/1 LSE Call

[Jeff Garzik]

insecure wrote:
> That sounds reasonable, but today's RAM throughput is on the order
> of 1GB/s, not 100Mb/s. 'Out of L1' theory can't explain 100Mb/s ceiling
> it seems.


cp(1) data, at least, will never ever be in L1.  Copying data you need 
to look at the ends of the pipeline -- hard drive throughput, PCI bus 
bandwidth, FSB bandwidth, speed at which ext2/3 allocates blocks, and 
similar things are likely bottlenecks.

You'll never hit RAM bandwidth limits, unless your copies are extremely 
tiny, and entirely in L2 or pagecache.

	Jeff



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