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Installing memory – Apple Power Mac G5 User Manual

Page 47

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Chapter 3

Working Inside Your Computer

47

Installing Memory

Depending upon the model, your Power Mac G5 has four or eight dual inline memory
module (DIMM) slots for Double-Data-Rate (DDR) synchronous dynamic random-access
memory (SDRAM) devices. Your computer comes with a minimum of 256 MB of
random access memory (RAM), installed as a pair of 128 MB DIMMs in two of the DIMM
slots. You can install additional pairs of DIMMs in the open DIMM slots on your
computer’s main logic board.

DIMMs must be installed in equal-sized pairs and fit these specifications:

400 MHz, PC 3200 DIMMs

2.5 volt (V)

184-pin module

Maximum number of memory devices on DDR SDRAM: 16

Nonparity

No error-correcting codes (NECC)

Unbuffered (registered or buffered DDR SDRAM cannot be used)

Important:

Memory from older Macintosh computers may not be compatible with

your Power Mac G5.

Note: When purchasing DDR SDRAM for use in Macintosh computers, make sure that
the memory vendor conforms to the JEDEC (Joint Electron Device Engineering Council)
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. To check the
compatibility of your DDR SDRAM DIMMs, see the Macintosh Products Guide on
Apple’s website at www.apple.com/guide. You can purchase Apple-branded memory
online from the Apple Store at store.apple.com.