1 512 vs 2 256...I need some benchmarks proving 2 is better

I am working on a project, and I need to get either a review or some benchmarks. I need a comparison of 1 module of DDR RAM vs 2 modules in an nForce 2 board. I need to do a comparision on how much faster dual channel is.

Do you guys know of any reviews, or anything dealing with this? I'd really like it to be run on one of the nForce 2 boards...but anything will be fine.

Thanks

Frost Byte