PCI to PCI-X Performance Comparison

[fmnemeth@rockwellcollins.com]

To all, a question,

Does anyone have any data or metrics to indicate how much of a performance
impact PCI-X has over conventional PCI? I understand that the clock rate
itself will give me additional performance, e.g. 2x improvement going from
33 MHz to 66 MHz. But clock rate by itself doesn't tell the whole story
here, since there are some protocol differences between PCI and PCI-X. Does
anyone have any hard data that you would like to share that demonstrates
the improvement that the PCI-X *protocol* buys you over conventional PCI?

Stated another way, performance improvement can be stated by the following
formula:

     Performance Improvement = Clock Multiplier * Protocol Multiplier

What value can i assign to the Protocol Multiplier, or what range of
values? And based on what *real-world* data?

Thank you in advance for your reply,
mike nemeth
Rockwell Collins, Inc.
fmnemeth@rockwellcollins.com

{Expressed herein is my opinion and not that of Rockwell Collins, Inc.}