Double Data Rate (a type of random access memory see RAM)--The next generation of the current SDRAM. DDR finds its foundations on the same design core of SDRAM, yet adds advances to enhance its speed capabilities. As a result, DDR allows data to be sent on both the rising and falling edges of clock cycles in a data burst, delivering twice the bandwidth of standard SDRAMS. DDR essentially doubles the memory speed from SDRAMs without increasing the clock frequency.
Dude you really need to upgrade your mainboard and go DDR, that PC133 is teh sux