iMac (Late 2006): Memory Specifications
Note: If you do install a 2 GB SO-DIMM in both the bottom and top memory slots of the computer, the About This Mac window and Apple System Profiler will both show that you have 4 GB of SDRAM installed. However, Activity Monitor and other similar applications will reveal that only 3 GB of SDRAM has been addressed for use by the computer.
Sun Baked said:I guess this answers it sort of ... seems the DMA and hardware addresses probably suck up the rest. Basically the same as the Windows users saw with the chipset.
Nutter said:The odd thing is that the iMac developer note states that "additional RAM must be installed in pairs of equal sizes."
I'm confused. How is 3GB possible in that case?