ddr ddr2 and ddr3 are all basicly the same in terms of performance. they just each require a different type of slot to plug into. they just jump in speeds of 400 per line.
ddr goes up to 400
ddr2 goes up to 800
ddr3 goes up to 1200.
ddr4 goes up to 1600
ddr5 goes up to 2000.
so when you see videocards with ddr4 or ddr5 you can assume ddr4 has memory speeds between 1200-1600 and ddr5 has them between 1600-2000. anything running faster than those are running out of spec.
so ddr2-1200 is basicly just high end ddr2-800 that is tested to run at those speeds. kinda.
however as the speed ramps up so do the length of the latencies of the timings. making the performance increase very minimal if not worse.
for instance all of these have the exact same performance. (ignoring the possible (AL) for DDR2, and i havnt looked up DDR3 (AL) so im not sure if it has any ) "The additional latency (AL) is usually found on the memory module technical specs (usually a PDF file for downloading on the manufacturer website)."
ddr-400 running 2-2-2-5
ddr2-800 (AL0) running 4-4-4-10
ddr3-1200 running 6-6-6-15
you can find this by doing the math.
the clock tick duration for memory speeds
Memory.........................Clock Tick Duration (each one)
DDR266.........................7.5 ns
DDR333.........................6 ns
DDR400 and DDR2-400.....5 ns
DDR2-533......................3.75 ns
DDR2-667......................3 ns
DDR2-800......................2.5 ns
i wrote a post quite a long time ago concerning the relationship between performance and the frequency & latency of timings of ram.
so if you are interested in learning more about memory performance and timings heres the info.
http://www.ocforums.com/showthread.php?t=446389
and here is the source.
http://www.hardwaresecrets.com/article/167/4
