Interesting results from this guy http://www.overclock.net/graphics-ca...70-vs-sli.html
Triple 5870s easily beat two 480s in most cases and even three 480s. The 480s just didn't scale as well in a 3-way config. I kinda want to get a 3rd 5870 and experiment now. I'd never use 3-way 5870 on the current mobo though since that means I'd have to sacrifice hardware PhysX.