Dell Vostro 220 (Late 2008) - Manual (Page 104)

104
Memory Module(s)
Replacing or Adding a Memory Module
NOTICE:
Do not install ECC memory modules.
NOTICE:
If you remove your original memory modules from the computer during a
memory upgrade, keep them separate from any new modules, even if you
purchased the new modules from Dell. If possible, do not pair an original memory
module with a new memory module. Otherwise, your computer may not start
properly. The recommended memory configurations for Vostro 420 are:
1) A pair of matched memory modules installed in DIMM connectors 1 and 2, or
2) A pair of matched memory modules installed in DIMM connectors 1 and 2 and
another matched pair installed in DIMM connectors 3 and 4.
NOTE:
If you install mixed pairs of PC2-5300 (DDR2 667-MHz) and PC2-6400 (DDR2
800-MHz) memory modules, the modules function at the speed of the slowest
module installed.
NOTE:
Ensure that you install a single memory module in DIMM connector 1, the
connector closest to the processor, before you install modules in any other
connector.
NOTE:
Vostro 420 can accommodate four DIMMs; Vostro 220 and Vostro 220s can
accommodate two DIMMs.
1 Pair A: matched pair of memory
modules in connectors DIMM_1 and
DIMM_2 2 Pair B: matched pair of memory
modules in connectors DIMM_3 and
DIMM_4
2
1