Disk I/O - too slow?

James Drabb JDrabb at tampabay.rr.com
Tue Feb 24 03:30:55 UTC 2004


On Mon, 2004-02-23 at 20:30, Don Levey wrote:
> So...  I've got DMA enabled, Multiple I/O, EIDE 32-bit and lookahead
> enabled in my /etc/sysconfig/harddisks file.  Running that hdparm line
> gives me:
> 
> /dev/hdb: 
> Timing buffer-cache reads:   1204 MB in  2.00 seconds = 601.49 MB/sec
> Timing buffered disk reads:   96 MB in  3.00 seconds =  31.97 MB/sec
> 
> ...clearly *not* fast.  This is a Maxtor Diamond ATA 120Gb drive,
> 7200rpm, on an ASUS A7V8X-X mb.  I'm running FC1 with a 2.6.3 kernel
> from kernel.org.  Any suggestions for speeding up my I/O (or more info
> to provide)?
> 
> TIA,  -Don

Those numbers are pretty respectable.  The 31.97 MB/sec sounds about
right for your average 7200 RPM hard drive.  On all the standard 7200
RPM drives I have, I get from 30 MB/s to 35 MB/s.  YOu need sata or scsi
if you want more then that.

Here is my laptop:

/dev/hda:
 Timing buffer-cache reads:   1500 MB in  2.00 seconds = 750.00 MB/sec
 Timing buffered disk reads:   68 MB in  3.06 seconds =  22.22 MB/sec
                                                                                          The first result is dependent on your memory speed. If I put the same hard drive in a system with slower memory, the first result will drop way down.  I have PC2100 in my laptop.  The second result is low because this laptop has a 4200 RPM drive.

What output do you get from:
    hdparm -i /dev/hda
and:
    hdparm /dev/hda

Jim Drabb
-- 
---------------------------------------------------------
The box said: "Requires Windows 98/2000/NT/XP or better."
So, I installed LINUX!
---------------------------------------------------------
James Drabb JR
Senior Programmer Analyst
Davenport, FL USA





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