Yeh i realise that...
so you are saying that DDR3 wont run slower than 800mhz?
800mhz datarate. That is the slow speed set by JEDEC for DDR3.
That is really a 400mhz bus with double data rate.
DDR3 has higher latencies, so DDR2 running (overclocked, since JEDEC does not recognize anything over 800mhz datarate for DDR2)@ 1066 will outperform DDR3 at the same datarate.
At anything less than 800mhz datarate, DDR3 is a major loss.