ATA (Re: AMD64 support in 5.x versions)

[James Van Artsdalen]

> Date: Tue, 13 Jan 2004 08:02:04 +0100
> From: Bill Squire <billsf at curacao.n2it.nl>

> I've got several large SCSI disks spinning and have since purchased an 
> ordinary ATA-133 IDE and a SATA drive.

SCSI vs. ATA can be a religious argument.

On the practical side if you have more than 4 GB of RAM I don't know
of any cost-effective solution that can address memory above 4 GB
directly, without using bounce-buffers.  I understand that some
Adaptec SCSI host adapters can do this (PCI "dual address cycle" or a
full 64-bit bus if available) without resorting to exotic RAID
controllers.

Highpoint sells an RR-1820 PCI-X (64-bit 133 MHz) serial ATA controller
but I cannot get them to send me any technical documentation and
cannot get it to work with Windows with the supplied drivers.  Silicon
Image has a 3124 chip which is PCI-X and ought to be able to directly
address more than 4 GB of RAM but I don't know of any card that uses
this yet.

I have 8 GB of RAM and use a HighPoint 1542 sATA controller, and am no
doubt exercising the bounce buffers extensively.  This seems entirely
stable but for performance I wouldn't want to do it with a disk-bound
system in a production environment.