On Sat, Aug 28, 1999 at 05:46:50PM -0700, Skip Harrison wrote:
> 2. Applied the 2_2_10_uniform-ide-6_20_genam_patch
I've only tried up to the 2.2.10.uniform-ide-6.20.eridanus.patch so far.
> Using "hdparm" on the IBM drive, I get 17 MB/sec. Granted, 17 is faster than
> 13, but is it UDMA 66?
I suspect so.
> If I shut off UDMA 66 mode on the IBM drive, I still get 17 MB/sec, so it
> does not seem to make any difference if UDMA 66 it is on of off.
That doesn't surprise me. The 66MHz burst speed will be increasingly
important as drive densities increase. I suppose it would matter more
if you had a slow cpu or many drives. But I have not tried to
measure the difference between 33 and 66.
> I saw a "PDC20262.warning" file at the
> ftp.us.kernel.org/pub/linux/kernel/people/hedrick/ page. (The PDC20262 is
> the chip on the Promise Ultra 66 card). In it Andre Hedrick said
> that "you will have to call idex=ata66 to inform the driver of the
> existance". I assume he means that one would have to do an "append
> ide2=ata66" at boot time to the LILO prompt, or set up a LILO boot option
> for the kernel that I complied in support for the Promise card. I have
> tried both, but still do not get any higher than 17 MB/sec.
I didn't do any of that. I do have CONFIG_IDEDMA_AUTO=y and
IDEDMA_PCI_EXPERIMENTAL=y, CONFIG_BLK_DEV_IDEDMA=y, CONFIG_BLK_DEV_PDC202XX=y,
and PDC202XX_FORCE_BURST_BIT=y.
> Has anyone gotten anything any faster than 17 MB/sec out of a Promise Ultra
> 66 card (On one drive, not RAIDed yet)? I tackle the RAID1 setup after I am
> happy I have got the Max out of the Promise card....
I got some new, pre-production, Seagate ST328040A, 7200rpm 28GB ATA-4 drives.
Using bonnie, I get sustained block reads at 24MB/s on the outer cylinders,
and almost 18MB/s on the inner ones. This is the fastest sustained rate
I've personally seen on any drive, ATA or SCSI. I suppose there are
faster drives out there, I just haven't seen them.
But I didn't check them on udma-33.
Jan Edler
NEC Research Institute
