The Power Macintosh G4 (AGP Graphics, or G4 Multiprocessor, aka Sawtooth) logic board boasts four DIMM slots which accommodate 64MB, 128MB, 256MB or 512MB PC100 SDRAM (3.3-volt, unbuffered, 64-bit-wide, 168-pin, running at 8ns and 125MHz). These slots support up to 1.5GB of PC100 SDRAM (999MB maximum per application program) using the following DIMMs:
- 32MB, 64MB, or 128MB DIMMs (64-bit-wide, 64-Mbit technology)
- 128MB or 256MB DIMMs (64-bit-wide, 128-Mbit technology)
- 512MB DIMMs (64-bit-wide, 256-Mbit technology)
As there is no DRAM soldered to the logic board, the G4 (AGP Graphics) requires at least one DIMM to boot. Apple does recommend that DIMMs be installed in slot 1 first (J19), then in J20, J21, and J22, in order. As the Uni-North IC memory controller on the Sawtooth logic board supports only linear memory organization, no benefit accrues from installing SDRAM DIMMs in matched pairs, and DIMMs (installed in any slot and any order) are addressed as a contiguous memory array.
Originally, the max memory installable in Sawtooth was 1GB, in the form of four (4) 256MB 128Mbit pieces. With the release of G4 Firmware Update 2.4 (5-26-2k), memory configurations up to 2GB are physically conceivable in Sawtooth using four (4) 512MB SDRAM DIMMs. Due to limitations in MacOS 9.04, the max memory configuration useable at this time for the G4 (AGP Graphics) is 1.5GB.
Display memory on the AGP ATI Rage Pro graphics card is separate from main memory. Display memory consists of 16MB 140MHz SDRAM devices configured along a 128-bit data bus. Display memory cannot be expanded by the user. Analog displays enjoy support for pixel depths of 8-bits, 16-bits, or 32-bits, and resolutions up to 1280 x 1024. Resolutions up to 1920 x 1080 are feasible, but only in 8-bit or 16-bit color. Digital "flat-panel" displays can utilize color depths between 8-bits and 32-bits, with a maximum resolution of 1600 x 1024.
|Logic Board RAM||None|
|Supported DIMMs||32MB, 64MB, 128MB, 256MB, 512MB.|
|Number DIMM Slots||Four(4).|
|Supported VRAM||16MB included on Rage 128 Pro AGP Video Card.|
|Number VRAM Slots||None. Not Upgradable.|
|L2 Cache Supported?||1 MB of Backside Level 2 Cache running at half the processor speed.|
|DIMM Type||168-pin SDRAM, 3.3v PC-100 CAS-2 64-bit, 8ns/125MHz.|