Specifications

Memory Power Macintosh - 2 1
DIMMs
Whereas SIMMs have 72-pins, DIMMs have
168 pins. The extra pins provide a 64-bit
data path, compared to a 32-bit data path for
SIMMs. In addition, DIMMs do not have to be
installed in pairs like the SIMMs on earlier
Macintosh models. (However, to take
advantage of memory interleaving, the DIMMs
should be installed in paired slots. See
“DIMMs” in Miscellaneous for more
information.)
Memory Configurations
The Power Macintosh 9500 Series logic
boards have 12 DRAM DIMM slots, each with
a 64-bit data bus. You can increase the
computer’s DRAM to a theoretical total of
1536 MB using 5-volt, 64-bit-wide,
168-pin fast-paged mode, 70 ns DIMMs.
When installing DRAM DIMMs in the Power
Macintosh 9500, fill slot A6 first, followed
by B6, then A5, followed by B5, and so on.
DRAM DIMMs can be installed individually;
however, to take advantage of memory
interleaving (see Note below), which
provides maximum performance, you must
install the DIMMs in matching pairs and in
paired slots (A6 and B6 first, then A5 and
B5, and so on).
DIMMs purchased from different
manufacturers can be paired as long as they
are the same size and speed.
Note: Memory interleaving allows the
computer to read or write to its memory
while other memory reads or writes are
occurring, thus providing for faster
performance.