by Bob » Tue Dec 30, 2014 3:21 am
It's going to depend on what editor you are using. Many of the consumer level editors don't do much in the way of graphic processing unit (gpu) acceleration at all and the video card makes little difference. Where consumer level editors use gpu acceleration, it's typically by using OpenGL which is supported by most, if not all, current video cards. But, editors vary, check the specifications for your editor. Professional level editors are a different story. Premiere Pro, for example uses gpu acceleration quite a bit and has more stringent requirements for the video card.
As for how much video ram, I'd say if you are going to get a new card, don't go lower than 1GB if you are using a 64-bit OS -- that's pretty common these days. Get more if doing substantial gpu acceleration.
Also, consider what other programs you will be using and whether they can benefit from a more capable video card.