Dual Channel DDR Question

[Zlatan]

I was wondering this: I read that Dual Channel only works if there are two or 4 memory sticks, but I was planning on getting 1.5 GB DDR, in 3 512 MB sticks. Will Dual Channel work if I put one 1024 MB stick and the other 512 MB, or basically this:

DDR 1GB PC3200 400Mhz
DDR 512MB PC3200 400Mhz


Same manufacturer.

 

[ghost]

Yeah Dual channel will work !

 

[suprasteve]

you sure? I thought they had to be the same size and designed to run dual channel for them to work that way. They will work regardless, but not in dual I thought. Back to the question though, are you getting 2 sticks, one 1gb and one 512, or are you getting 3 512's? If you're getting the 3 sticks, I know you can make two of them run dual channel and the other run regular assuming you get sticks that will work that way.

 

[Hairy_Lee]

they have to be the same size and the same ratings for best performance, i have heard that some will work ok with different sized modules but this generally doesn't happen.
it might work if you have the double sided 1Gb stick and a single sided 512Mb stick

 

[ghost]

Yeah Dual channel will work !

Witch it TRUE but the computer will only see 1024mb !!!! because the data blocks are split to two memory sticks at the same time instead of just one.

 

[Hairy_Lee]

yeah maybe, but its not exactly the desired way of it working.

 

[ghost]

True !

 

[Cromewell]

1.5GB will not work in dual channel unless you have an i945 or i955 chipset. They are the only ones I have seen so far that will take 2 different sized DIMMs and run them in dual channel.

 

[Zlatan]

I see. How about 2 512 MB sticks and 2 256 MB sticks?

DDR 512MB PC3200
DDR 512MB PC3200
DDR 256MB PC3200
DDR 256MB PC3200

 

[Cromewell]

That may work, just be sure to put them in the proper slots. What motherboard do you have?

 

[Zlatan]

I'm trying to build a new computer, so I havent really decided yet, but perhaps a Intel Desktop Board D945PSN if I decide to go with a P4 3.2 Ghz, or a Gigabyte GA-K8NF-9 if I decide to get an Athlon64 3500+ .

 

[Zlatan]

Oh, I forgot that the Intel one is DDR2.


And I'm leaning towards AMD for now.

 

[Cromewell]

Yeah the AMD system will probably be better performer. In the case of the Intel board any of the RAM combinations you have asked about already will yeild at least a partial dual channel

 

[Zlatan]

So you think that 2x512 + 2x256 would work with the Gigabyte MB?

 

[Zlatan]

Also, is Dual Channel support a MB feature only, or do the memory sticks themselves have to support it?

 

[Hairy_Lee]

its a motherboard feature on intel systems but a cpu function on amd systems. aslo, the matched ram (in most cases) allows this function to work

 

[Zlatan]

Sooo, bottom line is that 2x512 + 2x256 would work in dual channel if placed correctly?

 

[Hairy_Lee]

most likely, in my experience the 2 channels are colour coded. if you place each pair of same size ram in the same colour slots it should work

 

[Zlatan]

Thanks for your help mate, I think you lot have answered all my questions.


It's appriciated