aic performance (Was Re: SCSI speed with IBM DGVS09U (8 GB) hard drive, Linux)

[Jon Burchmore]

> /dev/sda:
>  Timing buffer-cache reads:   64 MB in  0.64 seconds =100.00 MB/sec
>  Timing buffered disk reads:  32 MB in  2.00 seconds =16.00 MB/sec

I haven't really been following this thread, but I'll assume that those
numbers were obtained on a P2/U2W system.  I'm getting the following numbers
out of my Dual Pentium 200MHz system w/2940UW and a WD Enterprise 4.2GB UW drive
(Linux 2.1.131-ac11):

/dev/sda:
 Timing buffer-cache reads:   64 MB in  1.96 seconds =32.65 MB/sec
 Timing buffered disk reads:  32 MB in  6.83 seconds = 4.69 MB/sec

Needless to say, I'm not too impressed since a P2-350 here at work w/UDMA IDE gets:

/dev/hda:
 Timing buffer-cache reads:   64 MB in  0.68 seconds =94.12 MB/sec
 Timing buffered disk reads:  32 MB in  2.64 seconds =12.12 MB/sec

But, I have some questions:

1.  Am I correct in thinking that the buffer-cache reads result is really a measure
of memory bandwidth?  If so then the first number kind of makes sense.

2.  Is this the kind of performance I should expect, or should I be getting better?

-Jon Burchmore

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