Re: high system cpu load during intense disk i/o

From: RafaÅ Bilski
Date: Tue Aug 07 2007 - 05:03:57 EST


Just tested (plain curiosity).
via82cxxx average result @533MHz:
/dev/hda:
Timing cached reads: 232 MB in 2.00 seconds = 115.93 MB/sec
Timing buffered disk reads: 64 MB in 3.12 seconds = 20.54 MB/sec
pata_via average result @533MHz:
/dev/sda:
Timing cached reads: 234 MB in 2.01 seconds = 116.27 MB/sec
Timing buffered disk reads: 82 MB in 3.05 seconds = 26.92 MB/sec

Interesting! I haven't tried libata myself on that system, I only have remote access to it so I'm a bit afraid...
Just change root=/dev/hda1 to append="root=/dev/sda1" in lilo.conf.
And change fstab. If You don't change "/" then system will go into single user mode after reboot.
Rafal, I hope that system you run hdparm on isn't the archlinux one! Is it easy to load an old kernel (even two years old) and do the same test? If it is, please let me know of the results.
I don't think it is possible. If I remember right kernel can't be older then glibc kernel headers.
Btw. My disk is 20GB 2,5" ATA33. I wonder how 26MB/s is possible. I don't expect more.

Thanks in advance,
Dimitris
Regards
RafaÅ

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