i use poser 4 and have a gig of ddr ram and its sweet.....depending on what your budget is......i know there is a difference when it comes to speed with the ddr and sdram but honestly ddr offers about a 20 % speed increase..... but really.....if it takes only 4 seconds to do some sort of operation with ddr .....it will take 5 seconds with the sdram ...... so if you really need that extra 1 sec then get the ddr if not then get the sdram.....what is fast in computer terms is not really much of a difference in human terms if you really want to visualize it......having a gig of ram wether it be ddr or sdram is still powerful nnuu