Michael Schuh wrote:
My results was that RELENG_5 is half as RELENG_4 fast by disk-access (ata-related). I have seen that RELENG_5 with GENERIC Kernel and only modified option HZ=2000. the spread begind with Gentoo (mentoided from me as the slowest, but errare humanum est) Gentoo : 100% time consumption RELENG_4: 67% time consumtion DrangonFly Rel1.2 69-72% time consumption (i think preemtion) RELENG_5 134% time consumtion these tests are made on physically the same Hardware (real, not equal system, same system, same disk, same RAM) with the command: # cd /; /usr/bin/time dd if=/dev/zero bs=1024 count=1024k of=zerofile;
You have shown that sequential IO is slower in RELENG_5 (I think others have observed this also - check out Google)...However, random IO is often more important for databases, and RELENG_5 can be faster than RELENG_4 (try out iozone, it makes testing this easy).
Also note that if your operating systems are installed in different parts of the same disk, then this will effect your results too - as some parts are faster than others.
With respect to Mysql performance, I would suspect threading or threading/kernel interaction as the culprit. (That reminds me, I don't recall seeing the original poster re-doing the tests with 6.0-CURRENT - that would be interesting).
cheers Mark _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "[EMAIL PROTECTED]"
