Got 6GB RAM on 2009 2.66 Mac Pro with 4870. The upcoming 5870 is $450. 12 GB (3x4GB) is $320 and 16 GB (4x4GB) is $425, and finally 24 GB (3x8GB) is $820. Which purchase or combo of purchase is best for video edit on Final Cut Pro? BTW, any additional benefits of getting the 5870? Gaming would be better (I game a little; X-Plane & Call of Duty), but wouldn't some apps off load to the GPU to make the CPU faster, though I don't know what those apps would be. I could run 2 displays with 5870 with ease, not sure if the 4870 can handle 2 displays. Thanks!