3D modelling applications can take advantage of available graphic hardware, and would considerably improve performance. I think I have quoted on these forums somewhere that, in the olden days, an topographic geological survey drawing in autocad would take much longer to open on an integrated graphics, but even back then discrete graphic cards outperformed them with reasonable margins.
With that being said, the CPU is still responsible for, "doing the math", as it were, in the creation of the drawing itself. And what is a movie, if not a lifelike drawing.
I do think it would be prudent to consider the actual hardware capability of the " olden days", before you compare it to the hardware capability of today, . What you'll find is specs that are laughable, 800Mhz Pentium 3 CPUs, 32 MB VRAM and on. Yet, they made movies (SD) with it. In fact, I d***ked around with Photoshop 5.5 in college. The discreet video cards were so slow, that half the time, they didn't redraw the screen after an edit.
Now, the only reason I bothered to enter this thread was to suggest that a massive outlay of cash in crossfire, (or SLI), video cards wasn't necessary, to play Blu-Ray, which is what a movie editor has to do. Hey, buy one good one first, and a SLI capable board, get the second one if you need it.
You don't need 300 FPS to play COD4 either, yet people publish "wowee gotta have one", specs of machines that will do it. Maybe it's to generate traffic on their site, and humor us "enthusiasts" .