Is DDR3 1333 a lot slower than DDR3 1600?
In real world situations you will not be able to notice the difference at all. Only in benchmark programs will it show. In some cases you can overclock the ram to run at the faster speed. In most cases the price is not that much different at all. DDR2 ram is silly expensive. You can sometimes buy a new motherboard and some DDR 3 RAM (enough to get you going) slap the same CPU and heatsink in for less than 4 GB of DDR2 ram.