What is up with DDR ram?

[jphudy]

Help me out guys, I know I will get answers here.

I am going to purchase a new P4 and motherboard. I need to buy new ram, and I see lots of differences in price.

I know that I am going to have an 800Mhz FSB, so I know I need 400Mhz DDR RAM. What is the purpose of the whole 2100, 2700, 3200 bit?

What is the difference between ECC and non ECC ram? Is it worth the price difference?

What about matched pairs? Is it better to have a matched pair or a single module?

Also, please let me know what differences in speed I can expect between these.

Thanks!

[vass0922]

PC3200 is 400Mhz FSB... so you'll need to buy 3200

Don't bother with ECC, its more for servers.. general mobo's won't even use it.

Matched pairs are for better performance for double data rate... but think this is only applicable to NForce2 boards.

Welcome to TechIMO

[tgxiii]

What chipset is your mobo? If it has a Springdale or Canterwood, you should get matching pairs of PC3200 RAM.

[phrozen_dreamz]

Some P4 mobo's support the Dual Channel DDR. That's your best bet for performance.



-Yo

[Omardeth]

i could be wrong but i don't think you have to get ddr400 . i think it , i could be wrong it works the same was as the cpu . the 400fsb is 200x4 if i am correct . so if the memory is treated the same wouldn't pc2100 work ?

[tgxiii]

PC2100 runs at DDR266. I was only suggesting matching pairs of PC3200 because PC3200 runs at DDR400. Since his P4 CPU runs at 800FSB, the dual channel DDR400 RAM would run at 400x2=800, the same speed as his FSB.

PC2100 would still work, but it will cause a bottleneck in his system.

[jphudy]

Springdale or Canterwood? What are the chipset numbers for these? Don't all P4 motherboards support dual channel DDR? Is there single channel DDR? Is it only important to have a matched pair for a dual channel?

I have not purchased a mobo yet. Still investigating.

[tgxiii]

Not all P4 motherboards have dual channel. I believe the VIA chipsets don't have dual channel, and Intel just released the 848, and it also doesn't have dual channel.

Springdale = 865
Canterwood = 875