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    SubjectRe: latest linus-2.5 BK broken
    Martin Dalecki <>:
    >Yes HT gives 12%. naive SMP gives 50% and good SMP (aka corssbar bus)
    >gives 70% for two CPU. All those numbers are well below the level
    >where more then 2-4 makes hardly any sense... Amdahl bites you still if you
    >read it like:

    I think your numbers are a little low - I've seen between 50%-80% on
    master/slave SMP depending on the job. 50% if both processess are heavily
    syscall oriented, 75% (or therabouts) when both processes are more normally
    balanced, and 80% if both processes are more compute bound.

    Good SMP, with a crossbar switch buss should give close to 95%. Good SMP
    alone should give about 75%.

    My expierence with good crossbar switch is based on Cray UNICOS/YMP/SV
    hardware. A well tuned hardware platform, and slightly less well tuned
    SMP implementation, though the UNICOS 10 rewrite may have fixed the
    SMP implementation.

    Jesse I Pollard, II

    Any opinions expressed are solely my own.
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