Do PCI-X slots take 33MHz PCI cards?

D

Dave (from the UK)

Subject pretty much says it all really.

I have a Compaq 160 MB/s SCSI card. I don't have it in front of me, but
it might be 33 MHz and not 66 MHz. I'm wondering if this will fit in a
PCI-X slot on a new motherboard.

If not, I might have to order the Tyan Thunder K8WE (S2895) motherboard

http://www.tyan.com/products/html/thunderk8we.html

with onboard SCSI, which adds quite a bit to the cost. It does have one
33 MHz PCI slots, but it might not be sufficient.


--
Dave K MCSE.

MCSE = Minefield Consultant and Solitaire Expert.

Please note my email address changes periodically to avoid spam.
It is always of the form: month-year@domain. Hitting reply will work
for a couple of months only. Later set it manually.
 
P

Paul

Subject pretty much says it all really.

I have a Compaq 160 MB/s SCSI card. I don't have it in front of me, but
it might be 33 MHz and not 66 MHz. I'm wondering if this will fit in a
PCI-X slot on a new motherboard.

If not, I might have to order the Tyan Thunder K8WE (S2895) motherboard

http://www.tyan.com/products/html/thunderk8we.html

with onboard SCSI, which adds quite a bit to the cost. It does have one
33 MHz PCI slots, but it might not be sufficient.

This is not an answer, but a pointer to a site that might help.

First of all, as I understand it, plugging a card with a slower
clock into a bus segment rated at a faster speed, results in all
cards sharing the same clock rate. If you stick a 33MHz card into a
bus segment with multiple slots, then the other cards in that
bus segment will share the same 33Mhz clock rate.

PCI cards have slots cut in them, and these indicate the
voltage compatibility. In the main part of the connector,
there is a 3.3V and a 5V slot. Where the extra 32 bits of
a 64 bit card appear, there is an additional slot which makes
room for the barrier at the end of a 32 bit socket. If your
Compaq card was a 5V only card, then it might not physically
fit into a higher speed 3.3V only bus. (Cards with both slots
cut in the 32 bit section of the connector, are universal cards
and can handle either I/O voltage choice.)

So, those are some issues I would investigate to start. If you'd
quoted a part number for the Compaq card, or knew if it was
actually an Adaptec card, or had a URL to a picture of the card,
it might be a bit easier to dig up more info.

The folks at forums.2cpu.com get more opportunities to play
with such combinations, than your average desktop builder.
Use the search facility over there, to dig up more practical
examples. (I have not been able to find a good web page with
a compatibility matrix for such issues, and the PCISig web
site doesn't appear to be interested in helping end users
in any way.)

For example, post #27 here:
http://forums.2cpu.com/showthread.php?t=69184&highlight=pci-x+compatibility

I think if you are going to play with K8WE, it might be
a good idea to register and post some questions about
the board on forums.2cpu.com . The above thread suggests
that Tyan support in Europe leaves a bit to be desired.

Paul
 
B

Bob Knowlden

Do you mean PCI-X or PCI-Express? (PCI-X is not an abbreviation for
PCI-Express.)

http://en.wikipedia.org/wiki/Pci-x

I think that an ordinary 33 MHz PCI card might work in a PCI-X slot, but it
wouldn't fit physically in any of the PCI-E versions I've seen (X1, X4,
X16).

Address scrambled. Replace nkbob with bobkn.
 
D

Dave (from the UK)

Bob said:
Do you mean PCI-X or PCI-Express? (PCI-X is not an abbreviation for
PCI-Express.)

http://en.wikipedia.org/wiki/Pci-x

I think that an ordinary 33 MHz PCI card might work in a PCI-X slot, but it
wouldn't fit physically in any of the PCI-E versions I've seen (X1, X4,
X16).


Cheers. I thought PCI-X was just another way of saying PCU-Express.
Seems not, so I had my wires crossed.

I'll have to check what the SCSI card is.


Address scrambled. Replace nkbob with bobkn.


--
Dave K MCSE.

MCSE = Minefield Consultant and Solitaire Expert.

Please note my email address changes periodically to avoid spam.
It is always of the form: month-year@domain. Hitting reply will work
for a couple of months only. Later set it manually.
 

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