iMac G5: double Ram faster than single

[Zammy-Sam]

The combined memory of all of the DIMMs installed is configured as a contiguous array of memory. The throughput of the 400 MHz memory bus is dependent on the DIMMs installed. If only one DIMM is installed, the memory bus is 64-bit. If two non-identical DIMMs are installed, there are two 64–bit memory buses. If two identical DIMMs are installed, the memory bus is 128-bit. Identical DIMM pairs have the same size and composition and provide the fastest and most efficient throughput.

More here

 

[Lycander]

Dual channel DDR, big whoop-dee-doo.

 

[DanTekGeek]

thats true on PCs as well.

 

[Viro]

That figures. They're using PC3200 RAM which has a clock speed of 200 MHz. Since it's DDR, most marketing types like to say that it's running at 400 MHz. Good to see that they're making it dual-channel so that the 800 MHz bus is fully used.