You will not see many differences on 3D.
You should focus on CPU if you wanna see huge changes.
the PC I'm using at my office sometimes stutters on viewport when I have a lot of polygon count, and Im using a decent processor Xeon E3-1230 V2 and only a GTX 650 card. So I think it will have a huge performance improvement when I use a High end graphics card on my own personal rig. And I'm planning to buy AMD 8350 btw, since Im on a low budget to buy a 4770k