Memory

I have a question about memory, concerning the memory bus size and the
amount of memory.
The last Apple iMac G5 accepts DDR PC 3200 Dimms, installed in two
slots. If the DIMMs are installed by pair, the memory bus will be a
128-bit bus. If the DIMMs used are not identical, or if only one DIMM is
used, the memory bus downgrades to 64 bits.
So basicaly, what should be prefered? A big amount of memory with a
64-bit memory bus or less memory but with a 128-bit memory bus?

For example, what is the most efficient:
2 x 256 MB and 128-bit
or
1 x 512 MB and 1 x 256 MB and 64-bit

I would appreciate if some "memory experts" could give their
explanations. Thanks!

--
Benoist

"Benoist Felsenheld" <benoistf@alussinan.org> wrote in message
news:1gkj02s.gip39819xc8weN%benoistf@alussinan.org...

" So basicaly, what should be prefered? A big amount of memory with a
64-bit memory bus or less memory but with a 128-bit memory bus? "


I am not a MAC expert, but if you look at the infrastructure of PC video
cards, you'll see that the 64-bit bus is a significantly lower performer
than the 128-bit bus. There is also a similar divide between the 128-bit
and 256-bit bus. I would go with the 512MB 128-bit setup rather than the
768MB 64-bit setup.