I still use my early 2008 Mac Pro. I purchased it from Apple with 2 gigs (1G x 2 sticks) and finally upgraded last year to 6 gigs (2G x 2 sticks; 1G x 2 sticks) and it runs Adobe CC without any lag for static designing. (photo editing, creating print and web graphics, UI designs, frontend development, local server development) I don't edit videos so I don't really need more.
I still use my early 2008 Mac Pro. I purchased it from Apple with 2 gigs (1G x 2 sticks) and finally upgraded last year to 6 gigs (2G x 2 sticks; 1G x 2 sticks) and it runs Adobe CC without any lag for static designing. (photo editing, creating print and web graphics, UI designs, frontend development, local server development) I don't edit videos so I don't really need more.