bad performance on ATA promise controllers

[JoséM.Fandiño]

Hello friends,

 I'm having a problem with my home server (ASUS A7V133 motherboard) which has
a horrible performance with ATA disks connected to an integrated promise
controller.

Below you can see iozone results of the same disk connected to the primary/
secondary controller versus the promise one.

Promise ATA100 controller:
=========================
Version 1.02a       ------Sequential Output------ --Sequential Input- --Random-
                    -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
damocles         1G  7285  18  7235   3  5198   3 18830  58 19332   7 180.5   0


VIA 82C686 ATA100 controller:
============================
Version 1.02a       ------Sequential Output------ --Sequential Input- --Random-
                    -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
damocles         1G 24301  63 25047  11 13182   8 29843  85 30678  12 185.1   1

There is a big diference, 7MB/s connected in the promise and 24MB/s in the 686
and using UltraDMA-100 in both cases.
Transfers between ATA devices are even worse, certain combinations give me
transfer rates as low as 1MB/s :-?
I tried with other disks/ata cables and the results where identical.

If I boot GNU/Linux in the same machine all disks work as expected in
the promise controller, so this make me think that it's a specific problem
with FreeBSD.

Until now, I haven't had any luck searching in the mailing list archives
about this problem so I'm trying to asking here. Does anyone know where the
problem could be?

Thanks

** dmesg: 
http://www.fadesa.es/misc/promise.txt
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