PowerMac 6100/60 & 6100/60 AV 

8MB soldered on. 2 SIMM sockets in two banks. 80ns 
72-pin SIMMs or faster. Virtual memory, 32–bit addressing, 
video RAM.

Physical Memory: Any SIMMs smaller than 4 MB will not 
work.  Up to 72MB could be installed using two 32MB 
SIMMs.Each bank must either be empty or full.

The PowerPC 601 chip has a 32-bit, internal, or first-level 
(L1) cache memory.  All PowerMacs have a SIMM slot on 
their motherboards to accept an external L2 cache SIMM, 
which provides faster data throughput.  This slot can accept 
up to a 1 MB SIMM.

Extended Memory: The PowerPC 601 in the PowerMac 
6100/60 has a built–in Memory Management Unit.  The PowerMacs have the most powerful extended memory implementation to date.  With extended memory active, the PowerMac's code fragment manager will load a native-mode application's application code into memory only as necessary, allowing native-mode applications to use a smaller memory allocation.  The end result is that, compared to an equal amount of physical memory, more native applications can launch when extended memory is active.

Video RAM: The PowerMac 6100/60 has no VRAM -- the internal video is RAM-based, and can support 16-bit color on 14" monitors, and 8-bit color on 15" and 16" monitors.  The amount of RAM used depends on screen size and color depth.  The 6100/60 AV card comes with 2MB of VRAM, but only 1MB is available if the TV-video ports are active.  This AV card can drive a second monitor.

PowerMac 7100/66 & 7100/66 AV 

8MB soldered on. 4 SIMM sockets in two banks. 80ns 
72-pin SIMMs or faster. Virtual memory, 32–bit addressing, 
video RAM.

Physical Memory: Any SIMMs smaller than 4 MB will not 
work.  Up to 136MB could be installed using four 32MB 
SIMMs.  Each bank must either be empty or full.

The PowerPC 601 chip has a 32-bit, internal, or first-level 
(L1) cache memory.  All PowerMacs have a SIMM slot on 
their motherboards to accept an external L2 cache SIMM, 
which provides faster data throughput.  This slot can accept 
up to a 1 MB SIMM.

Extended Memory: The PowerPC 601 in the PowerMac 
7100/66 has a built–in Memory Management Unit.  The PowerMacs have the most powerful extended memory implementation to date.  The PowerMacs have the most powerful extended memory implementation to date.  With extended memory active, the PowerMac's code fragment manager will load a native-mode application's application code into memory only as necessary, allowing native-mode applications to use a smaller memory allocation.  The end result is that, compared to an equal amount of physical memory, more native applications can launch when extended memory is active.

Video RAM: The PowerMacs are the first Macs ever to support two monitors without additional hardware.  The non-AV 7100 comes with a video card in the PDS slot with  1MB of VRAM soldered–in (enough to support 24–bit color on a 14" monitor) and 4 additional sockets for a maximum of 2MB. The sockets are for special 68–pin 256K (only) SIMMs.  The 7100/66 AV card comes with 2MB of VRAM, but only 1MB is available if the TV-video ports are active.  The internal video in both the AV and non-AV uses RAM-based video, and can support 16-bit color on 14" monitors, and 8-bit color on 15" and 16" monitors.  The amount of RAM used depends on screen size and color depth.

PowerMac 8100/80 & 8100/80 AV 

8 SIMM sockets in four banks. 80ns 72-pin SIMMs or 
faster. Virtual memory, 32–bit addressing, video RAM.

Physical Memory: Any SIMMs smaller than 4 MB will not 
work.  Up to 256MB could be installed using four 32MB 
SIMMs.Each bank must either be empty or full.

The PowerPC 601 chip has a 32-bit, internal, or first-level 
(L1) cache memory.  All PowerMacs have a SIMM slot on 
their motherboards to accept an external L2 cache SIMM, 
which provides faster data throughput.  This slot can accept 
up to a 1 MB SIMM.  The PowerMac 8100 comes with a 
256KB SIMM already installed.

Extended Memory: The PowerPC 601 in the PowerMac 
8100/80 has a built–in Memory Management Unit.  The PowerMacs have the most powerful extended memory implementation to date.  With extended memory active, the PowerMac's code fragment manager will load a native-mode application's application code into memory only as necessary, allowing native-mode applications to use a smaller memory allocation.  The end result is that, compared to an equal amount of physical memory, more native applications can launch when extended memory is active.

Video RAM: The PowerMacs are the first Macs ever to support two monitors without additional hardware.  The non-AV 8100 comes with a video card in the PDS slot with  2MB of VRAM soldered–in (enough to support 24–bit color on a 16" monitor) and 4 additional sockets for a maximum of 4MB. The sockets are for special 68–pin 512K (only) SIMMs.  The 8100/80 AV card comes with 2MB of VRAM, but only 1MB is available if the TV-video ports are active.  The internal video in both the AV and non-AV uses RAM-based video, and can support 16-bit color on 14" monitors, and 8-bit color on 15" and 16" monitors.  The amount of RAM used depends on screen size and color depth.