Difference between DDR and SDR

[Garfield]

The subject asks it all. What is the difference? Thanks.

--Garfield

[WillysNut]

SDR and DDR RAM are similar in that they both synchronize with the system clock which has a rising and falling edge. SDR transfers data only on the rising edge of the clock cycle. DDR transfers on the rising and falling edges of the clocky cycle. So DDR can essentially transfer twice as much information per clock cycle.

[Iamghey]

that's why it's called double data rate

[Placid]

Besides what WillysNut said they are physically different sdram has 168 pins and one notch in the base.
Ddr has 184 pins and has one notch in the base.

[Garfield]

Oh, so DDR is 2x as good as SDR!!! That is what the SHUTTLE mobo supports that I'm putting into this new system. Thanks!

--Garfield