On Tue, 2004-01-06 at 20:01, Jason Clark wrote:
> I have been running some benchmarks using sql-bench to illustrate the
> scalability differences between dual and quad server configurations and
> opteron/xeon cpu's. First thing I noticed was that as far as cpu clock
> scalability, the tests seemed to work well and illustrate the difference
> between a 1.8Ghz cpu and a 2.0 GHz cpu. But, when it came to the difference
> between a dual or quad cpu configuration, the tests showed no increase at
> all. I realize the test is single threaded, but I assume that's just the
> perl portion of the test and shouldn't have any impact on the mysql test
> results. I had read in a SMP thread about mysql that MyISAM tables might be
> the culprit and that innodb would be a better choice for this type of a
> benchmark. Has anyone else tried comparing dual cpu results to quad and
> seen a similar result?
The thing with this test is it is single user. You mentioned this
correctly. So it runs single query at the time. MySQL does not uses
several CPUs to execute single query - only multiple connections may
benefit from several CPUs. In case of Innodb it is not 100% the case -
there are helper thread doing read-ahead and some other actions, but
still benefit from multiple CPUs for single user test will be small.
For multiple CPU configuration benchmark we use multi user tests.
Unfortunately these are not publicly released yet, being still in
development. We plan to release some of them to the public in coming 2
As you need to run benchmarks now I'll ask my colleague to send you
current version and help you with any difficulties you might run into
trying to set it up.
AS3AP is the multi user benchmark you're looking for. For CPU comparison
perhaps it would be best to run it with some 10 clients and 40Mb
You may publish it, linking from your article if you feel like Benchmark
used in your article shall be available for users to try it, just note
what this is pre-release version.
Peter Zaitsev, Full-Time Developer
MySQL AB, www.mysql.com
Want to swim with the dolphins? (April 14-16, 2004)