Share The Experience Of Dual Channel Ddr

I've bought a dell dimension 3000 desktop with 256MB. To add more memory, I find the clause "dual channel DDR". It says dual channel will give higher performance.

This make me headache and try to find out what is it.

Generally speaking, with this technology, the speed of memory I/O will be doubled.

So the question comes, how can I get the "dual channel". After research several days, I got these answers.

1 To support dual channel, the chips on your mother board must support dual channel, such as Intel 865, 875.

2 There is no dual channel DDR memory or non-dual channel DDR memory. To get dual channel, at least two memories is required.
Selection criteria is decided by the mother board chips. Some chips is flexible, you can use even different capacity memories, such as one 256MB and another one 512MB.
But intel chips is very strict, that's why it makes me headache:

a) DDR memory should be the same capacity, such as both 256MB or both 512MB.
The chips on the DDR memory should be the same capacity. It means if the number of chips on these memory are same, then it is ok. You may meet 4 chips, 8 chips memories, etc.
c) The chips of the memories should be both on single side or on double side. It means for 8 chips, all the chips should be on only one side or 4 chips each side.
d) The memory no need to be the same brand, same speed(system downgrade to the lowest speed automatically)

After got these, I check my memories, it is an NANYA 256MB DDR400 8 chips single side memory(Why doesn't dell choose Kingston?). I go to the shop and bought a Kingston 256MB DDR400 8 chips single side memory. Now the system is woking in the dual channel DDR mode.

Someone may confused when surf the internet.

The memory in desktop pc is normally Non-ECC memory. ECC is the verification bit. Normally ECC memory is for the work station or server. Choose carefully

The DDR memory of desktop is 184 pin. 200-pin is used in laptop.