Subject: Re: pciide performance on alpha
To: Thor Lancelot Simon <>
From: Andreas Johansson <>
List: port-alpha
Date: 08/12/1999 20:02:55
On Thu, 12 Aug 1999, Thor Lancelot Simon wrote:

> > Hi!
> > 
> > I have another question regarding pciide: Is there anyone that has seen
> > really good performance with pciide and the alpha?
> With my plain pc164 with its cmd0646 (DMA, not UltraDMA) controller, I get
> about 9MB/sec from a Maxtor disk that does about the same with UDMA on
> my x86 box.
> What kind of IDE disk do you have that can do 16MB/sec from the platters?!

It's a Maxtor 91728D8, 16GB disk. I think the 8GB variant reaches the
same performance. There is also a newer 20GB Maxtor that can read 21MB/s.

These figures were obtained by reading from the raw device with dd.
Sustained speed will be lower as the beginning of the disk is located
at the outmost part of the disk, where the speed is the highest. Usually
the transfer speed declines as you approach the innermost part of the

Actually, these new nice IDE disks are my main reason for trying to make
the Promise Ultra33 PCI IDE contoller card work - you certainly get much
for your money when buying IDE.