Messages in this thread | | | Date | Sun, 28 Oct 2001 21:42:17 +0000 | From | Jonathan Morton <> | Subject | Re: xmm2 - monitor Linux MM active/inactive lists graphically |
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> > Unfortunately, things didn't change on my first disk (IBM 7200rpm >> @home). I'm still getting low numbers, check the vmstat output at the >> end of the email. >> >> But, now I found something interesting, other two disk which are on >> the standard IDE controller work correctly (writing is at 17-22 >> MB/sec). The disk which doesn't work well is on the HPT366 interface, >> so that may be our culprit. Now I got the idea to check patches > > retrogradely to see where it started behaving poorely.
>This really reminds me of a problem I once had with a hard drive of >mine. It would usually go at 15-20MB/sec, but sometimes (under both >Linux and Windows) would slow down to maybe 350KB/sec. The slowdown, or >lack thereof, did seem to depend on the alignment of the stars. I lived >with it for a number of months, then started getting intermittent I/O >errors as well, as if the drive had bad sectors on disk. > >The problem turned out to be insufficient ventilation for the controller >board on the bottom of the drive
As an extra datapoint, my IBM Deskstar 60GXP's (40Gb version) runs slightly slower with writing than with reading. This is on a VIA 686a controller, UDMA/66 active. The drive also has plenty of air around it, being in a 5.25" bracket with fans in front.
Writing 1GB from /dev/zero takes 34.27s = 29.88MB/sec, 19% CPU Reading 1GB from test file takes 29.64s = 34.58MB/sec, 18% CPU
Hmm, that's almost as fast as the 10000rpm Ultrastar sited just above it, but with higher CPU usage. Ultrastar gets 36MB/sec on reading with hdparm, haven't tested write performance due to probable fragmentation.
Both tests conducted using 'dd bs=1k' on my 1GHz Athlon with 256Mb RAM. Test file is on a freshly-created ext2 filesystem starting at 10Gb into the 40Gb drive (knowing IBM's recent trend, this'll still be fairly close to the outer rim). Write test includes a sync at the end. Kernel is Linus 2.4.9, no relevant patches.
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