iMac September 2006 Developer Notes

[Sun Baked]

Haven't found the burning question in the Developer Note, but Apple did say something in a technote...

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.

Developer Notes ...

iMac_0609_SuperDrive Developer Note

iMac_0609_Combo Drive Developer Note

RAM Expansion Developer Notes Updated

 

[stuuke]

So are they limiting use of Ram with system software?

 

[Silentwave]

It has to do with the chipset and overhead and all sorts of mumbo jumbo- basically the existing chipset cannot allow OS X to address all 4 gigs at the moment, if i understand correctly.
Santa Rosa or a move to a full scale desktop set would fix this.