wasting the memory speed

Accroding to this diagaram
http://www.viatech.com/en/k7-series/kt600.jsp

If for example My computer has DDR 400 and the CPU FSB is 400. In this
case I am wasting my memory speed. I mean the memory can send/receive
data to/from the chipset at speed 800Mhz(400*2) but the CPU which
suppose to handle these data can only work at FSB =400Mhz (I know the
internal speed is more than 400Mhz) but what I want to say is that
while the memory can supply data to the CPU at speed 800 the FSB of
the CPU can only take data at speed 400Mhz (so the FSB will slow down
the traffic). In this case this is not good design, the better is to
have CPU with FSB 800 or Why I bother to install memory DDR400, while
DDR200 will give the same performance provided that the CPU is FSB400.

Am I right?? any help would be very much apprciate it. Thanks.


Thanks