Date: Thu, 09 Sep 2004 23:24:05 +0200 From: =?ISO-8859-1?Q?S=F8ren_Schmidt?= <sos@DeepCore.dk> To: Kevin Oberman <oberman@es.net> Cc: Bjoern Koenig <bkoenig@cs.tu-berlin.de> Subject: Re: poor ATA disk speed with ICH2 Message-ID: <4140C9F5.5090404@DeepCore.dk> In-Reply-To: <20040909210541.16C925D09@ptavv.es.net> References: <20040909210541.16C925D09@ptavv.es.net>
next in thread | previous in thread | raw e-mail | index | archive | help
Kevin Oberman wrote: >>>While the test is running, the disk being written to "sings" with the >>>frequency somewhat dependent on the size of the write. On read, I get >>>silence. When I copy my full disk (if=3D3Dad0 of=3D3Dad2), I can clear= ly he=3D >> >>ar >> >>>the sound of the actuator moving the heads constantly toward the end o= f=3D >> >>>the backup. I assume that they are being returned to track 0 on a >>>repeated basis. >> >>There should be no seeks on a lone write to the raw disk, if there is=3D= 20 >>you have HW problems as the driver doesn't issue any seeks at all then.= >> >>What disks are this BTW ? >=20 >=20 > This was RELENG_5 on the 6th at 22:55 UTC. cvsup from my local mirror, > so it may have been up to about 70 minutes old. >=20 > The "singing" only happens when running V5. I have no such sound when I= > do the same thing with V4.=20 I have no idea, there is nothing in the ATA driver that does extra=20 seeking, so the seek behavior must originate somewhere else, ie=20 something else issues disk requests besides your dd. You could=20 instrument the code and have it write out all LBA's it writes to on ad2=20 to see what gets sent to the disk. > The disk is an Toshiba MK4019GAX. 40 GB ATA100 5400RPM. I get the same > performance, though, when using an IBM (now Hitachi) 40GB, ATA100 > 5400RPM drive. What I am seeing looks a lot like what Bjoern was seeing= , > so it's not unique to this system. Hmm, do you have write cache en/dis-abled ? Just for the fun of it I dd'ed to from my laptop disk through the fs=20 though as I want to keep my data, but that shoudl only make performance=20 worse. Its an ich4 but that uses the same code as the ich2. atapci0: <Intel ICH4 UDMA100 controller> port=20 0x1860-0x186f,0x376,0x170-0x177,0x3f6,0x1f0-0x1f7 at device 31.1 on pci0 ad0: 76319MB <TOSHIBA MK8025GAS/KA023A> [155061/16/63] at ata0-master=20 UDMA100 dd if=3D/dev/zero of=3Dfil bs=3D512 (24474468 bytes/sec) dd if=3D/dev/zero of=3Dfil bs=3D1m (25091961 bytes/sec) thats copying for ~30s as well (reading doesn't make sense here). Both are close to what that disk can do, so there is nothing in the=20 driver thats prohibiting reaching the disks performance... -S=F8ren
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?4140C9F5.5090404>