Dual channel RAM question - Bandwidth versus capacity

[Agythiest]

I recently purchased a new system with a Gigabyte GA-K8N51GMF-9 mobo and an athlon 64 2ghz. The bus is supposedly 2000mhz. It supports up to 2GB DDR400 RAM, or up to 4GB DDR333 via 4 dual channel slots.

Now looking to buy RAM, I came up with an intersting question for my budget.

I could either get 1GB(2x512), at 333mhz each. Filling up two slots. So I'd have 1GB at 666mhz bandwidth.

Or, for the same price, I could get 4x128's for 512MB, but at 1332mhz.

I googled but couldn't seem to find any real bandwidth vs capacity comparision like that.

Which would provide better over-all preformance?

Note: Since that time I have found a better deal. 4x256 for a total of 1GB, and all four slots filled. 1332mhz total. I belive I'm going to go with that, but still haven't found an answer to my question, so I figured I would ask here..

Is capacity more important than bandwidth. Or would more bandwidth benefit more for general preformance than capacity would?

 

[JMMD]

Is this a gaming PC?

Here's what I would recommend.

Either:
http://www.newegg.com/Product/Product.asp?Item=N82E16820145449

or

http://www.newegg.com/Product/Product.asp?Item=N82E16820211014

or

http://www.newegg.com/Product/Product.asp?Item=N82E16820221133

 

[Didou]

Memory bandwidth does not work like that. It's dual channel meaning it has two channels, each channel is made of two memory slots (slots 1/3 identified as channel 1 & slots 2/4 as channel 2).

Each channel is capable of transferring data around 3.2 Gigabytes/s in an ideal theorical situation (hence the PC3200 name) but in most cases it doesn't reach this level. Since you have two channels, it could (once again in theory) transfer about 6.4 Gigabytes/s over both channels.

In your case, two memory modules or four will make both work in dual channel, the only difference is that some motherboards will lower the memory speed if you have four memory modules installed & each channel will transfer about 2.7GB/s (hence the PC2700 name) meaning 5.4GB/s over both channels.

Conclusion : get the pair of 512mb memory modules.