What is (in theory), the maximum bandwidth possible on DDR2?

[RamGuy]

What is in theory the maximum bandwidth possible on double-channel memory stocked on 1200MHz (DDR2-1200)?

2400 MB/s
4800 MB/s
9600 MB/s
or 19200 MB/s ?

 

[mpjesse]

Theoretically it's 19.2GB/s. But theoretical limits are almost never reached in practice.

 

[NotAPimecone]

To expand on mpjesse's answer, DDR (and DDR2) uses a 64-bit (8-byte) bus. The theoretical limit is the frequency (number of transfers per second) * the bus width (number of bytes per transfer). For 1200MHz RAM

1200MHz * 8 bytes = 9600 MB/s (single channel)

This is the number that is used in PC-XXXX (or PC2-XXXX for DDR2)

Dual channel adds another 64-bit channel, doubling the theoretical bandwidth to, as mpjesse said, 19200 MB/s, or 19.2 GB/s.