Re: mysql benchmarks

David Xu wrote:

> Gustavo A. Baratto wrote:
>
> > Since the last post just had freebsd numbers, I'm re-posting it 
> > including
> > Linux as well. Both linux and freebsd numbers were taken from the 
> > same box:
>
>
> ...
>
> Can you try TSC timer on FreeBSD ? someone reported that using TSC
> timer boosts performance of super-smack significantly.
>
> David Xu

"TSC" can be a few 100 times faster than gettimeofday(), but one needs 
to know
how to calibrate and convert it to timer because TSC is counter, not timer.

Also, if FreeBSD uses TSC to compare with Linux using gettimeofday,
it does not sound a fun.
gettimeofday is a very expensive function on all systems.
http://dsd.lbl.gov/DIDC/papers/imc-2003.pdf
tells how much it costs on some common systems, especially FreeBSD and 
Linux.

So, if both systems use gettimeofday, then slow may be somewhere else.

--
------------ Jin Guojun ----------- v --- jin@xxxxxxxxxxxxxx ---
Distributed Systems Department          http://www.dsd.lbl.gov/~jin
Lawrence Berkeley National Laboratory,  Berkeley, CA 94720

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