3.3V / 5V PCI Question

["William Benner" <william_benner@email.msn.com>]

Hello there,

I have a question about 3.3 Volt and 5 Volt PCI connectors.

Throughout the PCI's past, every peripheral board that I have ever seen has
been a 5V PCI board, characterized by the "notch" in the PCI connector
farthest from the bracket.

In reading the PCI spec, and the "PCI System Architecture" and "PCI Hardware
and Software" books, it says that there are 3V connectors and 5V connectors.

I have heard that 5V PCI boards will not fit in 3V PCI connectors, and that
if I have a 3V PCI connector, I will either need a 3V PCI board or a
"Universal" board (with two notches). Is this true?

When will I see 3V PCI connectors on motherboards?

I know that the latest processors from Intel are 3V only, and it makes sense
that the entire motherboard would benefit from running at only 3 Volts.

Here is the magic question: If the newest motherboards coming out had only
3V PCI connectors, what would that "do" to the plethora of existing 5V PCI
boards? Is this a PR and support nightmare waiting to happen?

Is the answer that the latest motherboards will have 5V PCI connectors (and
bus translators), even though the rest of the motherboard is 3V?

I am keenly interested in hearing from the PCI GURUs about this. But I think
that this could be a point of confusion and so the answer is of general
interest. Please reply to the PCI list. (Note that when you hit the reply
button on your e-mail, it replies directly to the person who sent the e-mail
and not the list.)

William Benner