The Quadra 840av has no system memory on its motherboard and has four 72-pin SIMM sockets for memory expansion to 128 MB.
The 840av ships with 8 MB of memory in the form of a single 8 MB SIMM. Each SIMM socket can be filled with a 4 MB, 8 MB, 16 MB, or 32 MB SIMM. (The 840av does not support 1 MB, 2 MB, or 64 MB SIMMs.) You can use different capacities in each socket. The 72-pin SIMMs must be 60ns or faster.
Apple warns against using composite SIMMs in the Quadra 840av.
VRAM, Where More Memory Means Less Speed
The 840av ships with 1 MB VRAM on the motherboard. You can upgrade this to 2 MB by installing four 256 KB VRAM SIMMs in the VRAM sockets.
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