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Re: CPU scaling

Alex Karasulu wrote:
Hi Howard,

I should be able to get a hold of an 8-way Xeon system in January sometime. I will be able to place the order for it on the 2nd.

Sounds great, thanks Alex.

    Interestingly, while 2 cores can get over 13,000 auths/second, and 4
    cores can
    get around 25,000 auths/second (using back-hdb), with all 8 cores
    it's only
    peaking at 29,000 auths/second. This tells me it's better to run two
    slapds in a mirrormode configuration on this box (4 cores per
    process) than to
    run a single process across all of the cores. Then I'd expect to hit
    auths/second total, pretty close to the limits of the ethernet

Well, I guessed wrong. The peak with two separate processes was still the same, 29,000 auths/second. Interestingly, the peak with only 6 cores was about 31,000 auths/second. It appears that we're memory bandwidth-limited.
-- Howard Chu
Chief Architect, Symas Corp. http://www.symas.com
Director, Highland Sun http://highlandsun.com/hyc/
Chief Architect, OpenLDAP http://www.openldap.org/project/