Kingston follows the trend and launches DDR2-modules. The modules are available in 400 and 533 MHz speeds.
”DDR2 memory chips will be available in Fine-pitch BGA (FBGA) chip packages for improved electrical and thermal characteristics. In addition, DDR2 memory chips will incorporate On-Die Termination (ODT) to minimize memory signal reflections at high speeds, thereby improving timing margins. DDR2 memory chips will come in capacities up to 4 Gigabits, allowing for higher-capacity modules.”
But since DDR2-modules doesn’t have the same number of pins and voltage requirements they are not backwards compatible. They have also been equipped with a special notch like the DDR have one, and SDRAm two, so it won’t fit in our regular DIMM-slots. Thereby preventing any ”accidental insertion into an incompatible motherboard”.