Dual Core vs Quad Core Battery life

I understand that from a theoretical perspective, quad core processors have the potential to do more computation with less power than dual core processors. This is because, put simply, two cores @ 1 ghz use less power than one core @ 2 ghz, and dynamic under/overclocking allows processors to do this.

On the other hand, if optimizations that involve downclocking inactive cores are inadequate, a quad core could very well use up more power than a dual core.

So my question is, with current Sandy Bridge laptops, when performing low intensity tasks, will I get better battery life with a quad core or a dual core? Actual tests from anandtech, tomshardware, etc. would be nice.

I remember an article (from anandtech I believe) that found virtually no battery life difference between dual cores and quad cores when performing low intensity tasks, but that article only concerned the latest MBP's, which may have OS-specific optimizations missing in windows.

 

It's about the same - SB CPUs turn off all but 1 core unless and until needed.