K P wrote:Note they ran the benchmark on an Opteron 285 instead of a Xeon with 16 GB of memory. Opteron peformance currently **SUCKS** with 2.6 series kernels under any kind of heavy I/O due to their cloning of the ancient 82489DX architecture for I/O interrupt access and performance. Looks like the test was stakced against Linux from the start. Should have used a Xeon system.
Sun's recently published SPECjbb_2005 numbers on Linux, Windows and
Solaris on their
Opteron system, and the Linux result is the lowest of the three by far:
Linux: http://www.spec.org/jbb2005/results/res2006q1/jbb2005-20060117-00062.html
Solaris: http://www.spec.org/jbb2005/results/res2006q1/jbb2005-20060117-00063.html
Windows: http://www.spec.org/jbb2005/results/res2006q1/jbb2005-20060117-00064.html
It's not evident if Sun spent any time analyzing and tuning the Linux
result. While the
majority of the tuning opportunities for SPECjbb_2005 are likely to be
in the JVM itself, I was
wondering (given the large spread between the OS's) if there were
other typical opportunities
to tune the Linux kernel for JVM performance and SPECjbb_2005.
There are some other results showing excellent scalability with SPECjbb_2005 on
Linux/Itanium (such as SGI's:
http://www.spec.org/jbb2005/results/res2006q2/ ), but it's
not clear if there are other opportunities for tuning unique to Linux
on Opteron, or Linux
in general that should be explored
Comments?
SpecJBB is a really frigging stupid benchmark. It's *much* more affected
by the stupid crap in Java (like their locking model) than anything in the
OS.
Best to find another benchmark, oh and preferably somebody vaguely
objective to run it ;-)
M.