Messages in this thread | | | Date | Thu, 3 Apr 2003 13:38:09 -0800 (PST) | From | "Peter L. Ashford" <> | Subject | Re: RAID 5 performance problems |
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Stephan,
> here benchmark from my system with an fasttrak-tx4 (same card jonathan > has) with WD1800BB :
The WD1800BB and the WD1200BB use the same technology (same data density, fewer platters). The streaming speed should be very similar.
> /dev/hde: > Timing buffer-cache reads: 128 MB in 0.28 seconds =457.14 MB/sec > Timing buffered disk reads: 64 MB in 1.37 seconds = 46.72 MB/sec > > WD1800BB on onboard ultra100 controller : > > /dev/hdo: > Timing buffer-cache reads: 128 MB in 0.28 seconds =457.14 MB/sec > Timing buffered disk reads: 64 MB in 1.58 seconds = 40.51 MB/sec > > WD1800BB on onboard ultra33 controller : > > /dev/hda: > Timing buffer-cache reads: 128 MB in 0.28 seconds =457.14 MB/sec > Timing buffered disk reads: 64 MB in 2.55 seconds = 25.10 MB/sec
OK. We've found a potential issue. Are the disks being identified as UDMA-33 or UDMA-66/100/133? The performance numbers agree too closely for this to be a coincidence. Check the boot logs.
Good luck. Peter Ashford
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