Any problem if using a PCI 2.2 expansion card on PCI 2.1 bus?

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stypikes

I'd like to add a USB 2.0/1394 combo card to an old PC.

I've found 3 cards, all of which are suitable for PCI 2.2 bus.
But that old PC has PCI 2.1 bus, according to its manual.

If I can't find any card that is suitable for PCI 2.1, can I just use a
PCI 2.2 card?
 
stypikes said:
I'd like to add a USB 2.0/1394 combo card to an old PC.

I've found 3 cards, all of which are suitable for PCI 2.2 bus.
But that old PC has PCI 2.1 bus, according to its manual.

If I can't find any card that is suitable for PCI 2.1, can I
just use a PCI 2.2 card?
Click to expand...

It looks like PCI 2.2 allows for 3.3V cards as well as 5.0v cards. If
it is a 3.3V card, it will be keyed differently and will not physically
fit into your PCI 2.1 slot. Or, at least that's how I read this:

http://en.wikipedia.org/wiki/Peripheral_Component_Interconnect

Since the enhancement listed for PCI 2.2 relies on that 3.3V service, I
would speculate that if the card fits in your slot, it will work.

This thread, though suggest differently:

|| So what you are saying is that 2.1 cards will work on 2.2
|| motherboards but if its the otherway around then its unsure.
|| So a 2.2 ONLY card may or may not work on a 2.1 motherboard
|| depending on whether the 3.3V rail was enabled by the
|| manufacturer.

| exactly!

http://forumz.tomshardware.com/hardware/PCI-ftopict214004.html

Perhaps I misundertand what "keyed" means in the context of these cards.
I thought that refers to the posts and notches in the slot and cards
that orients the connection, but it might just be what pins are live. I
must admit that I've never had a PCI card not fit into the slot, and
I've put a lot of new cards in old machines.

So, I guess my revised answer is: Maybe?
 
stypikes said:
I'd like to add a USB 2.0/1394 combo card to an old PC.

I've found 3 cards, all of which are suitable for PCI 2.2 bus.
But that old PC has PCI 2.1 bus, according to its manual.

If I can't find any card that is suitable for PCI 2.1, can I just use a
PCI 2.2 card?
Click to expand...

I wrote up a nice long reply, but decided not to post it,
because what it boils down to, is you're going to have to
plug it in and try it. There are no guarantees with old PCs,
and not a lot of predictive abilities, to guess at what will
work and what will not. (440BX era machines seemed to have
a few problems with modern cards, for example. And we still
don't know exactly why.)

The card keying on PCI cards, is there to prevent damage. But
other than that, many things can happen, and all you can do is
try the card and see what happens.

Combo cards are especially nasty, because of all the variations
on how they are designed. I would be much more worried about
that aspect, than the PCI bus revision number of 2.1 or 2.2.

Paul
 
stypikes said:
I'd like to add a USB 2.0/1394 combo card to an old PC.

I've found 3 cards, all of which are suitable for PCI 2.2 bus.
But that old PC has PCI 2.1 bus, according to its manual.

If I can't find any card that is suitable for PCI 2.1, can I just use a
PCI 2.2 card?
Click to expand...

I've never gotten a PCI 2.2 card to work in a PCI 2.1 slot, and I
don't think that the problem is just the voltage because I've had some
+3.3V-only PCI cards run fine in ancient Socket 7 mobos, unless the
mobo didn't have the +3.3V connected to the PCI slots (FIC/VIA VA-503+
was like that -- wouldn't even run at all when a Soyo/VIA USB 2.0 was
pluged in, but that card worked fine with an older FIC/VIA PA-2007
with a similar chipset).
 
larry moe 'n curly said:
I've never gotten a PCI 2.2 card to work in a PCI 2.1 slot, and I
don't think that the problem is just the voltage because I've had some
+3.3V-only PCI cards run fine in ancient Socket 7 mobos, unless the
mobo didn't have the +3.3V connected to the PCI slots (FIC/VIA VA-503+
was like that -- wouldn't even run at all when a Soyo/VIA USB 2.0 was
pluged in, but that card worked fine with an older FIC/VIA PA-2007
with a similar chipset).
Click to expand...

Thank you, folks, I appreciate all of your helpful replies.

Now I think I'll take bus to downtown next weekend, hoping to find a USB
2.0 card (whether a combo with 1394 or not) specifically for the old PCI
2.1 bus.

But first of all, do USB 2.0 cards for PCI 2.1 really exist? I checked
a few online computer stores, and googled for it, to no avail.
 
stypikes said:
larry moe 'n curly <[email protected]> wrote:
Click to expand...
I'd like to add a USB 2.0/1394 combo card to an old PC.

I've found 3 cards, all of which are suitable for PCI 2.2 bus.
But that old PC has PCI 2.1 bus, according to its manual.

If I can't find any card that is suitable for PCI 2.1, can I just
use a PCI 2.2 card?
Click to expand...
Now I think I'll take bus to downtown next weekend, hoping to find a USB
2.0 card (whether a combo with 1394 or not) specifically for the old PCI
2.1 bus.

But first of all, do USB 2.0 cards for PCI 2.1 really exist? I checked
a few online computer stores, and googled for it, to no avail.
Click to expand...

Try to get one based on an NEC brand USB 2.0 chip because they're the
least troublesome and the most compatible with other USB devices. A
month ago I bought this 3-internal/1-external port card for $7,
shipped (you have to specify a code for free shipping):

www.meritline.com/4-ports-usb-2-0-pci-card.html

They also offer several other models, including a 5-int/1-ext NEC card
for $3 more (out of stock) and USB 2.0/Firewire cards. Belkin and
Adaptec USB 2.0 cards, available almost everywhere, including Wal-
mart, also use NEC chips.

If you can't get an NEC-based card (large or small square chip with
160 pins), the safest other bet is probably a VIA-based one (oblong
128-pin chip). Avoid anything with an ALi USB 2.0 chip (small,
square, about 64 pins) on it.

www.usbman.com and www.everythingUSB.com are great sources of
information.
 
Great help, guys! I really appreciate it.
It's one and half hours of bus ride to downtown. It should be worthwhile
now.
 
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