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While some of the products mentioned on this page may no longer be available, the information about these products remains available to those who may need it.

Note: All 32MB and 64MB SIMMs listed on this page are high-quality 2k refresh. Chip-sets vary, but 2k refresh SIMMs invariably work error-free in most older PowerPC Macintosh computers, and those Quadras that accept 72-pin SIMMs. With the exception of the Quadra 840av, the Gurus have noticed no genuine benefit from the use of 60ns SIMMs in most older Macs. If you have recently installed a G3 daughtercard, however, or contemplate doing so in the future, we recommend 60ns pieces. If you are upgrading a Quadra 840av, you must install 60ns SIMMs. To receive 60ns SIMMs, simply place a note in the comments field of the secure RAM Order Form requesting them, and they will be substituted at no additional charge.

Note that Power Macs with 64-bit memory buses require 72-pin SIMMs in matched pairs. Such machines include the PPC 6100, the PPC 7100, the PPC 8100, and the Power Computing Power 100.

Please be advised that Apple does not endorse the use of 64MB SIMMs in Macintosh that accept 72-pin SIMMs. While they can be used without negative consequence in 6100-series Power Macs, other configurations remain untested. MacGurus does not recommend the use of 64MB SIMMs in any Mac besides the 6100 at this time. We'll repeat this statement for emphasis:

MacGurus does not recommend the use of 64MB SIMMs in any Mac besides the 6100 at this time.

Model number links below point to logic board diagrams elsewhere on this website. The diagrams may be useful to experienced Macintosh users in identifying significant motherboard landmarks and memory expansion slots. If you do not see a drawing for your Macintosh and need assistance, feel free to email a MacGurus support engineer. If you are in doubt about your ability to handle sensitive electronic components, please contact your local authorized Apple dealer. Don't void your warranty!


The SIMMs on this page are specifically designed to support:

  • Performa 630 to 640, Performa 5200, 6200 & 6300, Performa 6110CD to 6118CD, Performa 450, 460, 466, 467, 475, 476, 550, 560, 575, 577, 578, & 580CD

  • Apple Workgroup Servers 60 & 80

  • Centris 610, 650, 660AV

  • Quadra 605, 610, 630, 650, 660av, 800, 840av

  • Power Macintosh 6100, 6200, 7100, 8100

  • LC III, 475, 520, 550, 575, 580, 630

  • Macintosh TV, Color Classic II

  • Power Computing Power 80, 100, 110, 120

  • Laserwriter Pro 600, 630, 16/600PS, 12/600PS, Select 360, Select 310