memory upgrades

[Michael E. Anderson]

The SGI 4D/80 "architecture" does support use of 4Mb DRAM SIMM's, but the
actual hardware implementation of the main memory system will not support
more than 16MB of local (to the processor board) main memory. Main memory
may be expanded in 16MB increments up to a maximum total memory size of
144MB by installing main memory expansion boards (32MB per memory expansion
board). Up to 48MB could be installed on the processor board using 4MB SIMM's
if 2 PAL's were changed to modify the RAS decode. This has never been done at
SGI and I am not aware of any plans to do so in the future. The kernel should
be able to find any amount of main memory present up to 144MB (?256MB?)
regardless of the type.

Mike Anderson
Advanced Systems Division
Silicon Graphics, Inc.
Mountain View, CA
415 962-3437