Dual channel question. More RAM vs Faster

[Agythiest]

I've googled for a while now and can't seem to find a definitive answer for my question.

Basically my problem is that I just purchased a new computer with a Gigabyte GA-K8N51GMF-9 Motherboard (supports 4x dual channel) with an Athlon 64, not sure the core since I don't have the system yet. Supposedly a 2000mhz bus speed

So the question I was wondering is..

For all around proformance, which would benefit the system more?

1 GB (2x512) at 333mhz each, as I understand dual channel doubles that, so 666mhz total

Or say, filling up all four slots for a total of 512 (128x4) at a total of 1332mhz?
-edit- I found a better deal. 1GB(4x256) total of 1332mhz -edit-

I would go DDR400, except for future expandability, the mobo only supports up to 2GB DDR400, while it supports 4GB DDR333, as I read somewhere.

Am I correct in thinking the 4x256 would produce the best results?

[Airwolf]

Is 1GB the most you can have then?

In the ones listed, I believe you are correct, the 4x256 is the option to go for if you can't increase by more than 1GB.

[Agythiest]

Its capable of going up to 4GB, however I don't have to cash to go any higher than 1GB currently. So I believe tomorrow I'll buy the 256's.

But I'm still curious, if it was a choice between the 1GB at 666mhz or the 512 at 1332mhz, which would perform better?

[Agythiest]

Okay, I feel like an idiot.

I don't know what I was thinking, but it doesn't double the speed of the memory, it doubles the bandwidth.

IE: It doesn't make 2x333mhz 666mhz.

Its actually like..

PC3200 RAM has a bandwidth of 3.2GB/s. Having it dual channel makes it 6.4GB/s.