DDR1/2/3

[bobsmith1492]

So I understand more or less how regular DDR works as opposed to SDR (if that's what you call it). So what is the difference with DDR2 and DDR3?

 

[stevty2889]

Basicly they made changes that allowed higher clock speeds, athough right now, the higher latencies being used make current DDR-2 no faster than DDR performance wise. Thats all I really know, I'm sure there is somebody who can be a bit more specific on what the differances are.

 

[JustAnAverageGuy]

LostCircuits and Hexus had a few good articles describing the difference between DDR1 and DDR2 🙂

 

[Wahsapa]

http://en.wikipedia.org/wiki/DDR_SDRAM
http://en.wikipedia.org/wiki/DDR-2
http://en.wikipedia.org/wiki/DDR-III

 

[itachi]

basically, here's how it works.. a normal memory interface (controller to memory chip) is 64-bits wide, with ddr the interface is no different externally.. internally, the memory is 128-bits wide. the ddr controller (on the chip) sends half the data at one edge of the clock and the other half at the other edge. with ddr2, the memory is 256-bits wide internally.. the on-chip controller completes a send in 4 cycles, sending a quarter at each edge. ddr3 isn't really anything new.. it's more of an alternate specification to ddr2 that allows higher clock speeds and a smaller stamp, the architecture itself runs on the same principle as ddr2.

 

[bobsmith1492]

I don't see anything about DDRIII though.... does it also sacrifice latency for bandwidth?

 

[icarus4586]

There's no such thing as DDR3. Some graphics boards use GDDR3, which is DDR2 modified (I'm not sure how exactly) to be better suited for graphics.

 

[Fox5]

Originally posted by: icarus4586
There's no such thing as DDR3. Some graphics boards use GDDR3, which is DDR2 modified (I'm not sure how exactly) to be better suited for graphics.

I think it's just even lower latency, and maybe higher voltage.