iMac RAM

[macdatadrive]

Hello.
I am confused (yet again) by my iMac.

It is a
2.16 GHz Intel Core 2 Duo
4GB 667 MHz DDR2 SDRAM
white polycarbonate mac from late 2006

Reading the manual, apparently it can only hold 3GB of memory in total... HOW CAN IT HOLD 4 GB?

PLEASE HELP!!!!!

 

[Hellhammer]

Although these iMacs will accept up to a 2 GB SO-DIMM in each of the two memory slots, the iMac will only support 3 GB total memory. If you want to maximize the amount of SDRAM in your computer, install a 2 GB SO-DIMM in one slot and a 1 GB SO-DIMM in the other. . .
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.

The "Late 2006" iMac models have the same memory limitations as the "Late 2006" MacBook Pro "Core 2 Duo" models. Ultimately, 4 GB of RAM may be installed, but not all RAM in excess of 3 GB can be used due to the possibility of memory "overlap".

http://www.everymac.com/systems/apple/imac/faq_cd/imac-intel-how-to-upgrade-memory.html