Specifications

34 Chapter 3
Installing Memory
Your server uses Double-Data-Rate (DDR) Synchronous Dynamic Random-Access Memory
(SDRAM) in packages called Dual Inline Memory Modules (DIMM). You can install additional
DIMMs in the four DDR SDRAM slots on your server’s main logic board, up to a maximum of
2 gigabytes.
DIMMs must fit these specifications:
m PC 2700 DIMMs
m 2.5 volt (V)
m 64-bit wide, 184-pin module
m Maximum number of memory devices on DDR SDRAM is 16.
m Non parity
m No error correcting codes (ECC)
m Unbuffered; do not use registered or buffered DDR SDRAM.
If you install 512 MB DDR SDRAM, it must have 256 megabit (Mbit) devices. You can also
install 256 MB DDR SDRAM that has 256 Mbit or 128 Mbit devices. You can install different
DDR SDRAM DIMMs in any order in any memory slot. To check the compatibility of your
DDR SDRAM, see the Macintosh Products Guide on Apple’s website at www.apple.com/guide
Note: When purchasing DDR SDRAM for use in Macintosh servers, make sure that the
memory vendor conforms to the JEDEC specification. Check with your memory vendor to
ensure that the DDR SDRAM supports the correct timing modes and that the Serial Presence
Detect (SPD) feature has been programmed properly, as described in the JEDEC
specification. You can purchase Apple-branded memory online from the Apple Store at
store.apple.com
Important SDRAM from older Macintosh servers is not compatible with your Macintosh
Server G4. Do not use older SDRAM, even if it fits into the DDR SDRAM slots.