Re: 2.1.111: IDE DMA disabled?

Doug Ledford (
Thu, 30 Jul 1998 15:45:07 -0500

Chris Wedgwood wrote:
> On Thu, Jul 30, 1998 at 07:04:05PM +0200, Gerard Roudier wrote:
> > Donnot know about the cheesy Fireballs, but the Atlases used to
> > return QUEUE FULL even sometimes with 0 command disconnected when
> > they are flooded with short IOs and write caching is enabled.
> The fireball I have doesn't support tagged queueing.

Older Fireballs don't support tagged queueing. Newer Fireballs support it,
but have fixed tagged queue depths (8 for the Stratus and 15 for the
Tempest). However, the Tempest firmware will corrupt itself and become
totally useless if you keep 15 commands open for the majority of the time on
an extended basis. The drive will require a complete power cycle before it
will come back to life. The Atlas drives also have a fixed maximum queue
depth of 32 commands, but will return QUEUE_FULL for conditions other than
QUEUE_FULL if it simply isn't capable of taking another command at the
time. FWIW, I like the Atlas and Capella drives, the Flakyball drives
should be burned at a stake though.


Doug Ledford <> Opinions expressed are my own, but they should be everybody's.

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