How much faster is DDR ?

[farns]

I am a dumb newbie venturing onto the net for advice about a new system.
How much faster is DDR than SDR on these 3 systems: P4 1.6A, AXP1600-1800, Duron 1.3
I hope the price matches its performance but I have heard otherwise,any know some percentage gains I could get?

 

[herbage11]

DDR defined in my A+ certification book means Double Data Rate. I am guessing (buying soon but dont have it yet) that it is atleast twice as fast. I know I am going with it. 🙂

 

[farns]

Im hearing that for AMD systems the boost is only like 5-30% or something and not much more for P4s,I spose I have to get it as in 3 years or so SDR will be obsolete,thats my only reason...

 

[John]

DDR memory delivers twice the data that SDR SDRAM does, but it is not twice as fast. I would say you gain roughly 10~15% in performance.

 

[farns]

Thanks guys

So if it delivers twice as much data then it sounds to my uneducated ear like its being bottlenecked by the mobo or something else and that maybe its best to get it cos a coupla years away there might be hardware that takes advantage of it properly and gets more of a speed jump out of it than SDR?

If Im looking 3 or 4 years ahead is DDR a better option or will both prolly be old hat by then so just get whatevers best now?

 

[John]

The price difference between DDR & SDRAM is not all that much. You would be better off purchasing DDR IMHO.

 

[billyjak]

DDR reads and writes in one clock at the same time, SDram does it in 2 operations.
Therfore DDR will always read and write faster.

 

[Jonny]

I agree with John. I just bought 256 DDR tonight simply because SD is just no cheaper. Speaking of money, grr at high memory prices.

Then again, if you have a motherboard that doesnt support DDR right now, I'm not convinced it's worth the upgrade.

 

[BFG10K]

DDR is signifcantly faster than SDR RAM but it's not twice as fast. Also Pentium4s benefit more from utilising DDR memory over SDR memory than Palominos do.

 

[Bovinicus]

It will benefit the P4 the most because that CPU is the most memory bandwidth hungry of them all. Expect boosts of 20-30% on average. The XP and Morgan Duron will benefit less. The gains will be more like 5-20% on average. With the proper tweaking I think a little bit more of a difference can be made.