poor ATA disk speed with ICH2
oberman at es.net
Thu Sep 9 14:05:42 PDT 2004
> Date: Thu, 09 Sep 2004 22:37:31 +0200
> From: =?ISO-8859-1?Q?S=F8ren_Schmidt?= <sos at DeepCore.dk>
> Kevin Oberman wrote:
> > Here are the results of my last test back in May plus tests done on a
> > kernel built from sources downloaded on Sep. 6. Is that going to catch
> > your fix? I don't see much difference. Do you have version number I can=
> > check?
> Sep 6 should be fine if we are talking -current, on RELENG_5 it=20
> "depends" since the MFC was done on the 6'th..
> > Buffer V4 Read V4 Write V5 Read V5 Write =20
> > 512 8385790 8111781 6921714 5115853 7130873 5261294
> > 1k 15457027 14865113 12330562 7811422 12494677 7952281
> > 2k 25677856 25273251 19939822 10572186 20137339 10708676
> > 4k 27083255 25897711 27096896 12860586 27064850 12982472
> > 8k 27079563 26033768 27097726 14416520 27017494 14497783
> > 16k 27082575 Oops! 27082273 15316924 26936316 15374888
> > 32k 27080720 25908336 27100118 15816203 26977041 15853140
> > 64k 27079904 26008387 27096093 16073422 26939153 15938326
> > 128k 27055901 25928520 27095673 16073422
> > 256k 27076467 25918950 27090967 16118789
> > 512k 27045087 25987266 27077925 16006708
> > 1m 27026694 25738575 27060626 15879266
> > Read: dd if=3D/dev/ad2 of=3D/dev/null bs=3Dnnn
> > Write:dd if=3D/dev/zero of=3D/dev/ad2 bs=3Dnnn
> > All tests run for about 30 seconds.
> > All tests in single-user mode. Nothing on ad2 is mounted.
> > Debug (WITNESS, INVARIANTS, malloc checking) disabled.
> > 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=3Dad0 of=3Dad2), I can clearly he=
> > the sound of the actuator moving the heads constantly toward the end of=
> > 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=20
> you have HW problems as the driver doesn't issue any seeks at all then.
> What disks are this BTW ?
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.
The "singing" only happens when running V5. I have no such sound when I
do the same thing with V4.
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.
Once again, it's fine on V4.
And, it works on Windows. (I just had to say that. I have not
actually tested under Windows.)
R. Kevin Oberman, Network Engineer
Energy Sciences Network (ESnet)
Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)
E-mail: oberman at es.net Phone: +1 510 486-8634
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