DDR3 modules use the same 240-pin form factor used by DDR2 modules, but they are not inter-compatible. As you can see here, DDR2 and DDR3 modules have the middle notch in different locations to prevent plugging memory sticks into the wrong motherboard.
DDR3 platforms are expected to start shipping in mid-2007, but Super Talent will launch DDR3 modules well ahead of the motherboards.
DDR | DDR2 | DDR3 | |
Clock Speeds | 266, 333, 400 MHz | 400, 533, 667, 800 MHz | 800, 1066, 1333, 1600 MHz |
Voltage | 2.5V | 1.8V | 1.5V |
Chip Package | TSOP | FBGA | FBGA |
Chip Density | 256Mbit | 512Mbit | 1Gbit |
On Die Termination | No | Yes | Yes |
Prefetch | 2-bit | 4-bit | 8-bit |
DIMM | 184-pin | 240-pin | 240-pin |