To: Alexander Yurchenko <>
From: Manuel Bouyer <>
List: tech-kern
Date: 09/29/2004 14:52:49
On Wed, Sep 29, 2004 at 02:35:09PM +0400, Alexander Yurchenko wrote:
> You're perfectly correct, lba48 limitation is mostly artificial made by
> vendors, e.g. promise cards Manuel has mentioned can be fixed with bios
> upgrade.

There are hardware issues too: some adapters snoop the registers to
automatically adjust parameters, and get confused by the multiple
register writes.

> btw, on my dumb sectors reading perfomance tests there's some benefit in
> not using lba48 for short transfers since lba48 commands require 2 times
> more io registers writes.


Manuel Bouyer, LIP6, Universite Paris VI. 
     NetBSD: 24 ans d'experience feront toujours la difference