Can someone tell me what DDR ram speeds are comparable to what rambus speeds.

[coolred]

DDR 1600, 2100, 2700, 3300, 400

Rambus 800, 1066, ?

So many differant memory speeds, how many differant types are there and which ones correspond closely to each other.

 

[sean2002]

Rambus is dual channel in the 850-850E chipset and no matter what speed the DDR is, RAMBUS is the fastest platform for the P4, I believe PC-1066 RAMBUS single channel is the bandwith as PC-2100 DDR

 

[Fallen Kell]

ummm...not so sure about that sean... I believe the single chanel PC-800 is the same as DDR-400. But DDR 400 isn't really a spec yet, just that its rated to run at 400 mhz. And I am talking speed here as in mhz, not speed as in access latency, and transfer bandwidth. DDR is MUCH faster then Rambus in access latency, and I really mean MUCH faster. But the Rambus has overall more bandwidth to send data, thus can send more info to/from memory (that is when you assume that the sizes will be large). If you were to pit Rambus vs DDR and had to do read/write access for thousands of seperate 1 byte pieces of data, the DDR in theory is going to be faster because it can access each segment of its memory faster then Rambus can.

It really is compairing two very different things. Rambus is built to send large amounts of data across the bus. DDR was built to have fast access speeds and low latency. But, DDR is now getting bandwidth it needs to send large amounts of data efficently as well.

 

[Whitedog]

PC800 Single Channel = 1.6Gb/s bandwidth = PC1600 (DDR200)

Dual Channel PC800 = 3.2 GB/s bandwidth = PC3200 (DDR400)

Dual Channel PC1066 = 4.2 Gb/s bandwidth = NForce2 using Dual PC2100 (DDR266)

Hope that helps Coolred

BTW, just because the "bandwidth" is the same in the above comparisons, the performance isn't. There are other things involved which affect performance, i.e. Latency and bit rate... Which some benchies DDR does better and other benchies RAMBUS does better. It's really a catch22

Yes, RAMBUS is currently the choice platform for P4, but it someone comes out with an NForce2 equivilant (Dual Channel DDR) things may shift. We'll have to wait and see.

 

[charlie21]

Whitedog - already been done. Granite Bay offers dual channel DDR for the P4.

 

[sean2002]

Originally posted by: charlie21
Whitedog - already been done. Granite Bay offers dual channel DDR for the P4.

BTW the 850E with PC-1066 is still the fastest P4 Platform

 

[mrman3k]

If I were getting a P4 system right now, I would get the P4G8X, simply the best in my opinion. Too bad Asus doesnt make their mobos really attractive like other vendors are doing.