Developer Documentation
PATHHardware Documentation > PowerBook G3 Series 1999

Configuration of RAM SO-DIMMs

Table 4-6 shows information about the different sizes of SDRAM devices used in the memory modules. The device configuration column shows three numbers that characterize each type of device: the number of addresses, the number of data bits per access, and the number of internal banks. The fourth column in the table shows the size of each bank of devices, which is based on the number of internal banks in each device and the number of devices needed to make up the 8-byte width of the data bus. The last column shows the memory size of the largest SO-DIMM with that device size that the PowerBook G3 computer will accommodate.

Table 4-6 Sizes of RAM expansion devices and modules 

Device size

Device
configuration

Devices
per bank

Size of
each bank

Size of
SO-DIMM

16 Mbits 2M x 4 x 2 16 32 MB 32 MB
16 Mbits 1M x 8 x 2 8 16 MB 32 MB
16 Mbits 512K x 16 x 2 4 8 MB 32 MB
64 Mbits 8M x 4 x 2 16 128 MB 128 MB
64 Mbits 4M x 4 x 4 16 128 MB 128 MB
64 Mbits 4M x 8 x 2 8 64 MB 128 MB
64 Mbits 2M x 8 x 4 8 64 MB 128 MB
64 Mbits 2M x 16 x 2 4 32 MB 128 MB
64 Mbits 1M x 16 x 4 4 32 MB 128 MB
64 Mbits 1M x 32 x 2 2 16 MB 128 MB
64 Mbits 512K x 32 x 4 2 16 MB 128 MB
128 Mbits 4M x 8 x 4 8 128 MB 256 MB
128 Mbits 2M x 16 x 4 4 64 MB 256 MB

The computer accepts either one or two SO-DIMMs. The bottom slot can accommodate a 1.5-inch SO-DIMM with up to 128 MB of SDRAM. The top slot can accommodate a 2.0-inch SO-DIMM with up to 256 MB of SDRAM. The memory controller configures the combined memory of the SO-DIMMs into a contiguous array of memory addresses.

Note

The PowerBook G3 Series computer does not support memory interleaving, so installing two SO-DIMMs of the same size does not result in any performance gain.


© 1999 Apple Computer, Inc. – (Last Updated 29 April 99)