Memory Information
	RAM Speed DIMM type On Board RAM Number of DIMM Slots Supported sizes in MB Maximum RAM Virtual Memory On Board VRAM Number of VRAM slots Cache DIMM slot Cache DIMM size	70ns 168 pin 0 8 4, 8, 16, 32, 64 512MB 1GB See VRAM See VRAM Yes 1MB

Notes

The Power Macintosh 7500/100 uses DRAM Dual In-line Memory Modules (DIMMs) instead of DRAM SIMMs. Whereas SIMMs have 72 pins, DIMMs have 168 pins. The extra pins provide a 64-bit data path, compared to a 32-bit data path for SIMMs. In addition, DIMMs do not have to be installed in pairs like the SIMMs on earlier Macintosh models. (However, to take advantage of memory interleaving, the DIMMs should be installed in paired slots. See "Memory Configurations" in Basics for more information.) Important: Single In-line Memory Modules (SIMMs) used in previous Macintosh models are NOT compatible with the Power Macintosh 7500/100. Important: This computer also uses VRAM DIMMs (112-pin 70ns or faster) instead of VRAM SIMMs. The VRAM SIMMs used in earlier Power Macintosh models are not compatible. Memory Configurations The Power Macintosh 7500 logic board has eight DRAM DIMM slots, each with a 64-bit data bus. You can increase the computer's DRAM to a total of 512 MB using 5-volt, 64-bit-wide, 168-pin fast-paged mode, 70ns DIMMs. Note: The Power Macintosh 7500 does not have any main memory soldered to the logic board. At least one RAM DIMM must be present for the computer to operate. DRAM SIMMs can be installed individually; however, if you wish to take advantage of the computer's interleaving* capability, which provides maximum performance, you must install the DIMMs in matching pairs and in paired slots (A1 and B1 first, then A2 and B2, and so on). *Memory interleaving allows the computer to read or write its memory while other memory reads or writes are occurring, thus providing for fast performance. For a pair of DIMMs to function as a single 128-bit wide pair, they must be of the same type and size. Note:DIMMs purchased from different manufacturers can be paired as long as they are the same size and speed.

VRAM Information

"On Board" in context of the Power Macintosh 7200, 7500, and 8500 indicates that 1 or more VRAM slots are taken up with DIMMS when they leave the factory: thus, the 7200 has 3 available VRAM slots, while the 7500 and 8500 each have two available to reach the 4 MB VRAM maximum. The Power Macintosh 7200, 7500, and 8500 all support the same type of VRAM DIMM. The 7200 has VRAM soldered on the logic board. The Power Macintosh 7500, 8500, and 9500 have no VRAM soldered on the logic board. VRAM is expanded on the Power Macintosh 7200, 7500, and 8500 by adding VRAM DIMMs to the expansion slot(s) on the logic board. The VRAM DIMMs must be 112-pin fast-paged mode, with 70ns RAM access time or faster. The Power Macintosh 9500/120 VRAM is expandable by adding VRAM DIMMs to the video card. NOTE: Power Macintosh 9500/120 customers can get a VRAM upgrade from ATI Technologies, Inc. No VRAM upgrade is available from Apple. Power Macintosh Family VRAM Included Maximum 7200 1 MB Logic Board 4 MB 7500 2 MB via DIMMs 4 MB 8500 2 MB via DIMMs 4 MB 9500/120 2 MB on video card 4 MB