The first generation of workstations from SGI were based on MC680x0 Multibus CPU boards, third-party IO controllers, and SGI's Geometry Engine based graphics subsystem, which could be up to a half-dozen boards.

The model 3120 the RCS has (rebadged by CDC as a Cyber 910) has a 68020 CPU, and a graphics system with 12 Geometry Engine chips.

Manufacturer	Silicon Graphics Inc.
Model	3120
Classification	Workstation
Introduced	1989
Word Size	32 Bits
Implementation	MC68020 Microprocessor
Registers	16
Logical Address	32 Bits
Physical Address	?
Memory Type	MOS

IP2 CPU board:

FP1 Floating Point board:

Excelan ethernet:

Boards from the graphics subsystem:

And the actual Geometry Engine chips: