Apple Mac Pro (Memory DIMMs Replacement) - Manual (Page 4)

073-1246 Rev. B 4 © 2009 Apple Inc. All rights reserved.
8-Core Memory
Eight-core computers
have eight memory slots,
four per processor. You
can install 1 GB, 2 GB, or 4
GB DIMMs for a total of up
to 32 GB of memory.
Each processor’s memory
controller has three
memory channels. DIMM
slots 1, 2, 5, and 6 have
their own channels; slots
3 and 4 share a channel
and slots 7 and 8 share a
channel.
For optimal memory
bandwidth, all six memory
channels should be used,
and memory should be
balanced across the six
channels.
Note: Populating slot 4 or
8 slightly drops maximum
memory bandwidth,
but depending on the
applications used, overall
system performance may
benefit from the larger
amount of memory.
Memory Slot Utility
If you have Fill in these slots
Two DIMMs 1 and 2
Three DIMMs 1, 2, and 3
Four DIMMs 1, 2, and 5, 6
Six DIMMs 1, 2, 3 and 5, 6, 7
Eight DIMMs 1, 2, 3, 4 and 5, 6, 7, 8
If you install different-size DIMMs in your computer, follow the order in the tables above. If the
DIMM configuration you install doesn’t provide optimized performance, the Memory Slot Utility
will appear on screen and recommend an improved configuration. To use the Memory Slot
Utility again, go to /System/Library/Core Services.