One limitation of JEDEC SDRAM is that the theoretical limitation of the design is 125 MHz, though technology advances may allow up to 133 MHz operation. It is obvious that bus speeds will need to increase well beyond that in order for memory bandwidth to keep up with future processors. There are several competing new standards on the horizon that are very promising, however most of them require special pinouts, smaller bus widths, or other design considerations. In the short term, Double Data Rate SDRAM looks very appealing. Essentially, this design allows the activation of output operations on the chip to occur on both the rising and falling edge of the clock. Currently, only the rising edge signals an event to occur, so the DDR SDRAM design can effectively double the speed of operation up to at least 200 MHz.
There is already one Socket 7 chipset that has support for DDR SDRAM, and more will certainly follow if manufacturers decide to make this memory available. In this industry, many times it is the first to market that gains the support, rather than the best technology.