Now also Micron with DDR400
Yesterday, Micron sold the first DDR400 chips to SIS. Micron moved straight away with Samsung, who had already shipped their chips a few days ago. SIS needs the DDR400 chips to test its new chipset for the Pentium 4, the SIS648.
However, these chips are still manufactured in DDR-I format as for the current memory chips DDR266 and DDR333. The disadvantage of this procedure is that these modules can only tolerate a maximum of 200 MHz clock frequency. For higher clock frequencies the DDR-II format has to be used, which is more expensive to produce. One advantage of the DDR-II format is the lower operating voltage of only 1.8 V compared to 2.5 V for conventional modules. The first test samples of the DDR400 chips in the future DDR-II format are not expected for a few months; series production will probably only start in 2003. You also have to wait until 2003 for the even higher DDR533.