Why is MySQL nearly twice as fast on Linux?

[Thomas Hurst]

* JG (amd64list at jpgsworld.com) wrote:

> At 03:45 PM 5/24/2004 +0100, you wrote:
> > Still, if we're going to be comparing with results from Linux which
> > are near the peak of it's performance curve we don't want to be
> > running in the middle of our much lower one.
>
> Why would you assume Linux is near the peak of it's performance curve?

I don't mean generally (the curve of super-smack results across various
tunings); I mean the curve you plot with a single set of tunings as you
increase the number of clients; performance peaks around $numcpu clients
and then drops off as you increase load -- the values being quoted for
Linux seem to be around $numcpu level clients.

IIRC (heh, pinch of salt time ;) at 30 clients Linux got about 55-65%
the performance it got at 4 (numcpu for a HTT dual Xeon), but don't take
my word for it (I'll check later if necessary, although without similar
hardware to compare against I doubt it's going to be very helpful).

> Nobody that I have seen so far, including myself, has even tried to tweak
> Linux or MySQL on Linux beyond and out-of-the-box installation to get
> results that far exceed the performance of FreeBSD.

I think the most we did was use my-huge.cnf, which is the bundled config
suggested for >1GB systems.  You're right that there's not a lot of need
to tune to get damn good results on Linux though; at least on this
relatively small benchmark.

> Yeah I'm sorry I flamed you there... I'm just very frustrated over here.

After recompiling MySQL about 20 times in a row, I fully understand :/

-- 
Thomas 'Freaky' Hurst  -  freaky at aagh.net  -  http://www.aagh.net/