I'm a little late to this party, but I may have some info to contribute.
I don't recall how the six slot (genuine - Umax is special) Macs are mapped (I think A1, B1, C1 are the top three slots and D2, E2, F2 are the bottom three), but I do know that they are separate busses controlled by independent Bandit chips. One set of slots (A1, B1, C1) share a Bandit with the Grand Central IC on the motherboard. So these slots also share PCI bandwidth with the on-board devices like ethernet, sound, SCSI, etc. One could experience a small performance gain by putting high-bandwidth cards in the lower slots. In particular, slots A1 and D2 have a peculiarity of software/hardware design that gives them slightly better cache performance.
Oh, check out this post on AppleFritter: http://www.applefritter.com/node/9310#comment-27565
That, in turn, quotes Jeff Walther whose name I seem to recognize for some reason...
Peace,
Drew
_________________
Power to the PowerPC!
I don't recall how the six slot (genuine - Umax is special) Macs are mapped (I think A1, B1, C1 are the top three slots and D2, E2, F2 are the bottom three), but I do know that they are separate busses controlled by independent Bandit chips. One set of slots (A1, B1, C1) share a Bandit with the Grand Central IC on the motherboard. So these slots also share PCI bandwidth with the on-board devices like ethernet, sound, SCSI, etc. One could experience a small performance gain by putting high-bandwidth cards in the lower slots. In particular, slots A1 and D2 have a peculiarity of software/hardware design that gives them slightly better cache performance.
Oh, check out this post on AppleFritter: http://www.applefritter.com/node/9310#comment-27565
That, in turn, quotes Jeff Walther whose name I seem to recognize for some reason...
Peace,
Drew
_________________
Power to the PowerPC!