is ddr2 800 faster than ddr PC 3200 even though the latency in PC 3200 is higher cas latency of 2 vs.4 or 5?

Answer 1

DDR 2 is a different type of RAM than DDR1....you cannot mix the two.

DDR2 800 is A LOT faster than DDR 400 (PC 3200) Normally a CAS latency of 2 is faster than 4, but in DDR2's case, 4 or 5 is pretty much the norm.

Intel LGA 775, and the new AMD AM2 utilizes DDR2, and some socket 478 motherboards.