Re: IDE-DMA strangeness (another one)

Andre M. Hedrick (
Wed, 2 Dec 1998 17:25:26 -0600 (CST)

On Wed, 2 Dec 1998, Rik van Riel wrote:

> > Not a bug...........8.4 MB/second is a UDMA drive at DMA mode 2
> > on an 430HX/VX/TX, and I bet the usable buffer is more.
> So that is the maximum speed I can expect from my IDE subsystem?
> Seems fair enough to me :)

Note really.......the example above is a UDMA drive running on a DMA mode
2 limited chipset..........

I get 12-13 rates with UDMA chipset amd UDMA Drive..........
My oldest UDMA drive is a brick at 8.7 a Quantum FB 3.2 ST
Next oldest UDMA drive is better at 9.8, a Quantum FB 6.4 ST
Here is the drive is better at 10.92, a Quantum FB 8.4 SE
The newest pair of drives are at 12.38, are Maxtor 6.8

As you see it is the drive.........all of these numbers are on the same
chipset.........the Quantum FB ST's are from memory.

> > > Some motherboards use a crippled controller for ide1 in the belief
> > > that it will only be used for cdroms.
> >
> > That is usually because of lazy BIOS writers/hackers (ass)(u)(me)
> > "Nobody will use more than two hardrives"
> :) I had 5, 3 IDE and 2 SCSI. And an ATAPI CDROM and a SCSI
> optical. Now one of the IDE drives is removed (slow, 250MB)
> and the others are repartitioned. With 4 disks your system
> can run pretty smooth....
> cheers,
> Rik -- now completely used to dvorak kbd layout...
> +-------------------------------------------------------------------+
> | Linux memory management tour guide. |
> | Scouting Vries cubscout leader. |
> +-------------------------------------------------------------------+

Andre Hedrick
The IDE-FNG for Linux
The APC UPS Specialist for Linux

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