How much RAM of what type does the Power Mac G5 support? Which models have four RAM slots and which models have eight RAM slots?

Depending on the model, the Power Macintosh G5 supports either PC2700, PC3200, or PC2-4200 DDR memory installed in matched pairs. Power Mac G5 systems with PCI expansion slots have four RAM slots and systems with PCI-X or PCI-Express (PCIe) expansion slots have eight RAM slots.

This information is provided on the specs page for each model, but for your convenience, details regarding compatible memory, number of memory slots, and maximum supported RAM also are provided below:

Power Mac G5	RAM Type	Slots	Max. RAM
1.6 (PCI)	333 MHz PC2700 DDR	4	4.0 GB
1.8 (PCI-X)	400 MHz PC3200 DDR	8	8.0 GB
2.0 DP (PCI-X)	400 MHz PC3200 DDR	8	8.0 GB
1.8 DP (PCI-X)	400 MHz PC3200 DDR	8	8.0 GB
1.8 DP (PCI)	400 MHz PC3200 DDR	4	4.0 GB
2.0 DP (PCI-X 2)	400 MHz PC3200 DDR	8	8.0 GB
2.5 DP (PCI-X)	400 MHz PC3200 DDR	8	8.0 GB
1.8 (PCI)	400 MHz PC3200 DDR	4	4.0 GB
2.0 DP (PCI)	400 MHz PC3200 DDR	4	4.0 GB
2.3 DP (PCI-X)	400 MHz PC3200 DDR	8	8.0 GB
2.7 DP (PCI-X)	400 MHz PC3200 DDR	8	8.0 GB
Dual Core (2.0)	533 MHz PC2-4200 DDR	8	16.0 GB
Dual Core (2.3)	533 MHz PC2-4200 DDR	8	16.0 GB
"Quad Core" (2.5)	533 MHz PC2-4200 DDR	8	16.0 GB

Please note that just because RAM meets the minimum listed criteria does not mean that it will necessarily function as intended in a particular Mac. When buying memory, be sure to buy from a quality vendor that has tested their RAM with your Mac to ensure compatibility.

Site sponsor Other World Computing sells memory compatible with every Power Macintosh G5 model.