Date: Thu, 23 Jun 2005 11:50:36 -0700 From: ray@redshift.com To: freebsd-amd64@FreeBSD.org Cc: freebsd-amd64@FreeBSD.org Subject: Re: Slower MySQL inserts for AMD64/Opteron? Message-ID: <3.0.1.32.20050623115036.00acd818@pop.redshift.com> In-Reply-To: <20050623134319.GA43842@dragon.NUXI.org> References: <3.0.1.32.20050622104159.00a55450@pop.redshift.com> <3.0.1.32.20050622104159.00a55450@pop.redshift.com>
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Thanks, I will do that :-) When you speak about IDE/ATA, does that apply to SATA as well? Or just PATA? Ray At 06:43 AM 6/23/2005 -0700, David O'Brien wrote: | On Wed, Jun 22, 2005 at 10:41:59AM -0700, ray@redshift.com wrote: | > I did some benchmarks recently on a single 2.4Ghz Xeon against a Dual | > 246 Opteron and noticed when it came to MySQL inserts, the single Xeon | > was about 20% faster on inserts (and it actually had a slower hard | > drive, IDE vs SATA). The interesting thing is that the Dual Opterons | > was twice as fast retrieving the data using selects. | .. | > The Xeon was running 5.3/i386. I believe the AMD was running 5.4/AMD64. | | Note that in 5.4, the ATA subsystem runs without the Big-GIANT-Lock. CAM | (SCSI subsystem) still grabs GIANT. For a system with a single activity | going on (such as yours), I feel ATA can "out perform" SCSI doing some | things. Note that most IDE disks lie and always cache things. If MySQL | is doing fsync's to ensure the data is on disk, the ATA disks can seem | faster, but aren't as save and reliable than SCSI disks. There are many | reasons one uses SCSI over IDE disks. "Raw" performance isn't | necessarily one of them. | | Summary: please try an IDE disk in the Opteron machine. Preferable pull | the disk out of the Xeon, put it in the Opteron and re-run your | benchmark. | | -- | -- David (obrien@FreeBSD.org) | |
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