SL and multiple cores

I'm curious to learn about how SL works with multi-core CPUs. I have a 4 core CPU and have been leaving task manager open of late and watching what happens as I use SL. The first surprise was to see that frequently one core is pegged to 100% usage no matter what I am doing in SL, and the other cores show minimal usage. I would have thought that by now SL would take advantage of multiple cores, particularly since it is so CPU bound. But I have a Phenom 940 overclocked to 3.4 GHz and an Nvidia 260, so I was a little surprised to see a core maxed out like that. And it stays maxed out, even if I turn off volumes or find a relatively clear piece of sky to look at.

The next surprise was that everyone once in a while SL will appear to be more evenly balanced across multiple cores...without any of them maxed out.

There does not seem to be any rhyme or reason to when this happens. There does not seem to be anything I can do to trigger it, or that I do that can make it stop (not that I want to make it stop).

Does anyone know what the timetable is for better use of multiple cores in SL, and for an upgrade to it's compatibility with newer GFX cards? From what I understand, SL makes poor use of the power and features of modern cards. Certainly my experience has supported this as well.

Would also like to know if anyone has any direct experience of using SL with both a Phenom 940 and an i7 920, and what the difference has been. Based on my conversations with a few people it would seem that the i7 fairly dramatically outperforms the Phenom.

SL has tentatively entered the realm of multiple cores through a hidden command. Press ctrl-alt-d to open the advanced controls, and then confirm that you really meant to when the warning pops up. Under the new Advanced menu, go to the Rendering section and then highlight the option for multi-threading. SL will now use two cores.