DDR vs DDR2

[FalcomPSX]

According to this article at Anandtech, DDR2 will not outperform DDR1. I accept this as true as I have no reason not to. My question lies in another fact they put forth...

DDR2 is nearly identical to DDR1, with a few optimizations. The major optimizations include:

4-bit prefetch (up from 2-bit)
Enchanced Registers
Additive latency
FBGA Packaging
On Die Termination
DDR2 gets the majority of its punch from the 4 bit prefetch. DDR2 can effectively write/read four times the amount of data per clock cycle to/from the memory array. This effectively doubles the data bus speed while keeping the internal bus speed the same from DDR1.

Now, I like to consider myself a rational person, so if DDR2 can effective read/write 4x the amount of data per clock, and this effectively doubles the bus speed as they say it does, doesn't that directly contradict their claim that DDR2 won't out preform DDR? It seems logical to me that if you effective double the bus speed, you would expect to see some sort of performance gain, or at least I would. Would someone mind explaining this to me?

[JohnE.]

Hmm... that does seem odd. Maybe they're meaning DDR2 won't outperform DDR1 on a board that only supports DDR1? I'm just guessing... is DDR2 backwards compatible even?

[RamonGTP]

The beinift could be negated by the increased latency... My guess is that initially, DDR2 won't outperform DDR1, but as clock speeds increase it will scale better and outperform it.

[jkrohn]

Latency is one of the big issues. DDR-II will have to get up to about 667MHz Bus (Up from 400 and then 533) before it starts to outperform DDR.

Jkrohn

[FalcomPSX]

so DDR2 isn't all that great.....it just scales better but performs worse....hmm sounds like Intel's strategy...

[RedFury]

so DDR2 isn't all that great.....it just scales better but performs worse....hmm sounds like Intel's strategy...