I am not using RAID. I will have 4 HDs and 2Opt.
I would put 2 HDs and 2 Opts on the EIDE controler.
However, I have and extra Promis ATA 100 PCI card from my old PC. So, I
could install only the 2 OPTs on the card. Other devices will be, a SCSI
card for my scanners, a tele Modem. I will also have 2 more HDs on the MoBo
Promise Controller.
If I use the PCI card Promise controler will there be a speed advantage?
Will there be a resource problem?
In terms of speed, the Southbridge has a 266MB/sec bus feeding
the storage section. That means a SATA drive on the Southbridge
has a good path to work with. The primary and secondary IDE on
your Southbridge are limited to 100MB/sec or less, as ATA133 is
not supported (I don't think any Intel chipset supports it.)
The Promise 20378 is sitting on the PCI bus. The PCI bus has a
practical limit of maybe 110MB/sec. So, whether the Promise 20378
supports ATA100 or ATA133 is likely not too important, in
terms of transfer rate, as the PCI bus will cap the limit.
Your proposed ATA100 PCI card sits on the PCI bus. It will
not be going any faster than 100MB/sec on a single interface.
So, no speed advantage.
I would say, from an IDE perspective, you are pretty well limited
to the same degree, on all interfaces. Only detailed benchmarking
will uncover any subtle differences.
As for resources, there is a limit on how much low memory is
available to load controller BIOS code. What this means is,
depending on the order the controller BIOS are loaded in,
some controller might not have its code loaded. This will
prevent booting from the device in question, but won't
stop you from using a disk on it as a data drive.
Only time will tell - there is no way to tell in advance,
as Asus support for add-in cards is weak (i.e. nothing in the
interface will tell you what is going on at a low level - how
much of the 128KB low memory is in use).
If you wish to boot from the Promise ATA100, I would put the
card closer to slot 1. I think controller BIOS code is loaded
in slot order, so if the Promise ATA100 was in slot 1 and
the SCSI card was in slot 2, the Promise onboard ROM would
load before the SCSI onboard ROM. To achieve the desired
effect, swap cards around.
If you have a card which is interrupt latency sensitive, put
it in slot 1, leaving slot 5 blank (as slot 1 and slot 5 share
a physical interrupt line). Place the Promise ATA100 in slot 2,
if you want to try to boot from it. Place the SCSI card in slot 3,
as then its onboard ROM would load after the Promise card. If you
are really, really lucky, all ROMs will load.
Report back whatever you discover.
Paul
