Power Mac 4400-series

Motherboard Diagram by MacGurus
We appreciate your technical corrections and comments !

The PowerPC 603ev-based Power Mac 4400-series is the only Apple-branded Power Mac to utilize the Tanzania architecture marketed by Motorola and its licensees. Like other Tanzania variants, the 4400 has three DRAM DIMM slots and a 64-bit data bus, which require 3.3-volt, 64-bit-wide, 2k refresh, 168-pin unbuffered extended data out (EDO) JDEC-standard DIMMs with an access time of 60ns or faster.

Typically shipping with 16MB of RAM in the form of a single 16MB single-banked DIMM in slot 1, the 4400 requires at least one DIMM to boot due to a lack of soldered memory on the logic board.

The three DIMM slots are distinctly different from those found on previous Power Mac logic boards:

DIMMs in sizes of 8MB, 16MB, 32MB or 64MB may be utilized, in accordance with the above schema. If ordering for Slot 1, please note that fact in the Comments field of the MacGurus secure order form. The maximum memory supported by this logic board is 160MB, in the form of two 64MB DIMMs in slots 2 & 3, and a single single-banked 32MB DIMM in slot 1.

It should be noted that the 4400 does not require DIMMs to be installed in pairs, as the PSX memory controller does not support memory interleaving. But Apple technical documents are emphatic in recommending a 1.100 inch height for 4400 DIMMs, in accordance with the shortest form factor permitted in the JEDEC MO-161 specification. Due to the internal organization of this computer, taller DIMMs will be forced down into the DIMM sockets with excessive force, with undesirable consequences.

The Power Mac 4400 supports an optional 256k L2 cache DIMM with integrated cache controller. Apple technical documents intimate that Apple does not support the development of third-party L2 cache for this computer, despite the fact that the 160-pin cache expansion slot is identical to that found on Power Mac 5400 and Performa 6400 Alchemy motherboards.


Logic Board RAM None
Supported DIMMs 8MB, 16MB, 32MB, 64MB
Number DIMM Slots Three (4)
Number VRAM Slots One (3)
L2 Cache Supported? L2 DIMM: 256K Apple proprietary
DIMM Type 168-pin, EDO 64-bit, 2k refresh, 3.3v 60ns or faster

While some of the products mentioned on this page may no longer be available, the information about these products remains available to those who may need it.

With a single 120-pin video DIMM connector internally (Burndy Corporation ELF120GSC-3Z50), the 4400 series supports up to 4MB VRAM using either 3.3v SDRAM, or 3.3v SGRAM, in sizes of 1MB, 2MB, or 4MB. A single EDO 5v VRAM DIMM can also be utilized, but Apple technical documents note that the maximum usable size for an EDO VRAM DIMM is 2MB, as EDO DIMMs larger than 2MBs afford no additional performance due to the limited bandwidth characteristic of such modules. With a 4MB SGRAM or SDRAM DIMM, the 4400 can generate 32-bit color at resolutions up to 1280 x 1024.

Please be advised that the microprocessor link points to a page on Motorola's awesome website.

Back to Motherboards Directory