Dell Precision T5400 (Late 2007) - Manual (Page 188)

188 Adding and Replacing Parts
Memory Installation
Fully buffered DDR2 memory modules can also be installed in pairs of two; in
this case, the computer will continue to operate, but with a slight reduction
in performance. The pairs must be matched in size, rank, and organization.
Install memory modules in order of their labels on the system board; matched
sets of four should be installed first into DIMM slots 1-4 and then into
DIMM slots 5-8 on the system board. Pairs of memory should be first
installed into slots DIMM_1, and DIMM_2, then DIMM_3 and DIMM_4,
and so on.
NOTICE: Do not install non-ECC or unbuffered memory modules. Doing so may
cause the computer not to boot.
NOTE: DIMM slots 1-4 have white latches for easy identification. DIMM slot 5-8
have black latches.
Addressing Memory With 4-GB or Greater Configurations (32-bit
Operating Systems Only)
This computer supports a maximum of 32 GB of memory when eight 4-GB
DIMMs are installed. Current 32-bit operating systems, such as Microsoft ®
Windows ® XP and Widnows™ Vista, can use a maximum of 4 GB of address
space; however, the amount of memory available to the operating system is
1 fully buffered DIMM 2 information label
1
2