32bit slots and riser cards

Robert G. Brown rgb at phy.duke.edu
Thu Aug 28 16:49:06 EDT 2003

On Thu, 28 Aug 2003, Greg Lindahl wrote:

> On Thu, Aug 28, 2003 at 02:57:15PM +0200, Bogdan Costescu wrote:
> > the Myrinet card does not fit (keyed differently) into the 64bit PCI slots 
> > or 64bit risers. Is there some solution to this problem or do I have to go 
> > back to midi-tower cases ?
> Doesn't that mean that the Myrinet card is 5 volts, and you only have
> 3.3 volt PCI slots? It's such an old Myrinet card that I don't
> remember the details of when PCI got a 3.3 volt option.

I think that this is right, Greg -- the keying is related to voltage.

If your actual PCI slots are keyed correctly, they should be able to
manage either voltage (IIRC), but you may have to replace the risers.
We've had trouble getting risers that didn't key correctly or work
correctly for one kind of card or the other (or one motherboard or
another) in the past.  It sounds like this might be your problem if
you're referring to replacing the cases and not the motherboard itself.
Look around and see if you find better/different risers -- there are a
fair number of different kinds of risers out there, at least for 2U.


Robert G. Brown	                       http://www.phy.duke.edu/~rgb/
Duke University Dept. of Physics, Box 90305
Durham, N.C. 27708-0305
Phone: 1-919-660-2567  Fax: 919-660-2525     email:rgb at phy.duke.edu

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