As for motherboards with 64-bit PCI slots, there are
several. First
off, there
are several Alpha motherboards with 64-bit PCI slots. Then there
are the boards
for the Pentium III processors with the Serverworks chipsets. There are also
motherboards for Athlon-MP processors with 64-bit PCI slots (some of which are
also 66MHz slots). I know there were earlier motherboards for Pentium II and
Xeon processors with 64-bit PCI slots, but they weren't advertised
in the usual
places as they were more of a specialized board, but they were advertised in
some areas.
The newer non-AGP PowerMac's have a 64bit PCI slot as well.
It's generally the slot in which the video card resides.
Jeff
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