SATA/UDMA100 support on ATI RS300 chipset?

[Tom Samplonius]

On Wed, 05 Jan 2005 15:33:48 -0700, secmgr <security at jim-liesl.org> wrote:
> That would be ASUS who would have embedded the 3COM chip.  probably
> special order, which is why it didn't report back something recognized.
> The ATI chipset is pretty new vs the more tried and known
> nVIDIA/SiS/VIA/AMD  [South|North]bridges and the Intel hubs
>
> Running current can be "exciting".  Since you seem to have networking
> covered, you may want to look at a SATA pci card thats "known" to
> freebsd.  In theory, the box has two slots.
>
> jim

  The 3com chip is not recognized, since it very new.  It is mostly
used in laptops.

  SATA drives attached to the ATI RS300 works fine in 5.3-RELEASE,
except that FreeBSD detects the disk as UDMA33, and performance isn't
good.

  PATA disks have better performance on the Pundit-R, even though they
are also detected as UDMA33.  In fact, I wonder if PATA disks are
actually operating at UDMA66 or UDMA100, but FreeBSD doesn't know
this, as it it is treating the ATI controller as a generic ATA
controller.  The reason why I suspect this, is that my PATA disk can
do 30MB/s read, and I don't think it is possible to get 30MB/s through
a UDMA33 connection, especially with the ATA/IDE overhead.

  The question I have is, can I trick FreeBSD by adding the device ids
for the ATI chipset, at least for IDE?  It appears that all of the
nVIDIA/SiS/VIA/AMD [South|North]bridges are fairly similar as far as
the drivers are concerned.

Tom