Yay for B6 ! Yeah,...........don't expect any really vast improvement in rendertimes. I have a dual dualcore 3.2Ghz 2mbL2 cache Xeon machine running B5 and see only slightly faster rendertimes(about 15 - 20%), however, the 4Gb's of RAM will make working with much larger scene files alot easier(as far as saving and loading too), at least that's been my experience.

"Any club that would have me as a member is probably not worth joining" -Groucho Marx