actually, its wrong.
ddr400 is running at 200MHz clock speed, the DDR is dual data rate, hence 2 instructions at 200MHZ makes it equivlent to 400MhZ.
Bandwidth of DDR400 is PC3200. DDR-SDRAM is 64bit, so hence 400MHz * (64/8)bytes = 3200MB/s
Dual DDR doubles this bandwidth, to 6400MB/s, effectively the same as saying the speed is now 800MHz.
ECS L7VTA mobo
2 x 512MB DDR400 Geil Value Ram (w/blue hs)
NVidia GeForce4 MX 420
Seagate Barracuda 120GB, 7200Rpm, 8MB buffer (pata),
Seagate Barracuda 160GB, 7200Rpm, 8MB buffer (sata-ncq)
BTC1108IM dvd writer (8X)
Aopen 1648 dvd-rom
sunbeam fanbus controller
Philips 190X5 19\'\' LCD monitor 12ms