Apple Power Macintosh 4400 - Manual (Page 145)

About memory
You can have memory—dynamic random-access memory (DRAM), video
memory, or a cache—added to your computer in packages called Dual Inline
Memory Modules, or DIMMs.
DRAM configurations
The main logic board has three slots where DIMMs can be installed. Your
computer can use the following DRAM configurations:
DIMM slot number DIMM size DIMM banks Refresh count Device technology
1 8 MB Single 1K 16 Mbit
1 16 MB Single 2K 16 Mbit
1 32 MB Single 2K 16 Mbit
2 and 3 8 MB Single 1K 16 Mbit
2 and 3 16 MB Single or dual 1K 16 Mbit
2 and 3 16 MB Single or dual 2K 16 Mbit
2 and 3 32 MB Single or dual 2K 16 Mbit
2 and 3 64 MB Dual only 2K 16 Mbit
WARNING To avoid damaging your computer and expansion card, do not
attempt to install any expansion card without first checking the
documentation for that card. If the documentation specifies that an
Apple-certified technician must install the card (usually because
the installation requires special training or tools), consult the service
and support information that came with your computer for instructions
on how to contact an Apple-authorized service provider or Apple for
assistance. If you attempt to install the card yourself, any damage you
may cause to your computer or card will not be covered by the limited
warranty on your computer. If the card is not an Apple-labeled product,
check with an Apple-authorized dealer or service provider to see if you
can install it yourself.
145 Installing Expansion Cards and Additional Memory