Re: UDMA 100 / PIIX4 question

Jeremy Jackson (jerj@coplanar.net)
Mon, 19 Mar 2001 14:55:53 -0500


Tim Moore wrote:

> quintaq@yahoo.co.uk wrote:
> > I have an IBM DTLA 307030 (ATA 100 / UDMA 5) on an 815e board (Asus CUSL2), which has a PIIX4 controller.
> > ...
> > My problem is that (according to hdparm -t), I never get a better transfer rate than approximately 15.8 Mb/sec. I achieve this when DMA is enabled, - without it I fall back to about 5 Mb /sec. No amount of fiddling with other hdparm settings makes any difference.
> > ...
>
> 15MB/s for hdparm is about right.

You should be able to get about 30 MB/s at the start of the disk (zone 0) according to IBM's datasheet at

http://ssdweb01.storage.ibm.com/techsup/hddtech/prodspec/dtla_spw.pdf

so if you were testing say /dev/hda1 which is at the start of the disk it should be faster.

Try hdparm -i /dev/hda (or whatever) .. . note the reported MaxMultSect= value,
and put it in place of X in command:

hdparm -u 1 -d 1 -m X -c 1 /dev/hda

Cheers,

Jeremy

PS - please let me know if this fixed your problem, since I have a system
with the same motherboard.

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