have to install 2 dimms to get DDR benefits?

[omyek]

i'm reading the manual for the asus p4p800 and it says for "dual-channel" operation i need to install a pair of dimms. if only one dimm is installed, i'm running in "single-channel" mode. so in order to benefit from ddr ram, do i need to install two dimms?

or does it not matter and i will i get the same performance from a single 512 ddr ram as opposed two a pair of 256?

thanks.

 

[DaveSimmons]

The i865/i875 chipset articles on the Anandtech site should explain this in detail, but the short answer is:

You need a matched pair of DDR sticks in the proper memory slots to get the full speed of the motherboard / dual channel operation. With the 2 sticks the motherboard reads from / writes to "both at once" for double the memory speed. If you only have one stick you only get half the speed.

 

[Jeff7]

Originally posted by: omyek
i'm reading the manual for the asus p4p800 and it says for "dual-channel" operation i need to install a pair of dimms. if only one dimm is installed, i'm running in "single-channel" mode. so in order to benefit from ddr ram, do i need to install two dimms?

or does it not matter and i will i get the same performance from a single 512 ddr ram as opposed two a pair of 256?

thanks.

In single-channel mode, you still get the benefits of DDR RAM. However, with two matched sticks, then it will operate in dual channel mode - one memory controller for each stick, though I don't think it will give you twice the performance. It'll give a slight increase; on my 8RDA+ (nForce2 chipset) it increased memory read speeds by under 10%, according to AIDA32.

 

[pspada]

Unlike Dave's "short" anwser, mine actually is:

Yes, you need 2 dimms to benefit from dual channel operation. Both need to be DDR.