which is better in which circumstanc?

Solution
The 6300 is better for gaming. Either would work for a computer just browsing the web and doing normal tasks, much weaker cpu's than those two would work for that.
It depends upon your budget. For gaming i use a 6300 (overclocked) and that works fine. For heavier gaming you would need an even better processor. For browsing the web and writing documents etc. either one of those processors would eat that up. The 6300 is a little more "future proof" but honestly those tasks are very easy and you should be fine for a while. Depending on what games you plan to play you may want to go with the 8 core. Of course that's really a 4 core but that's another story 🙂 good luck!
 


I already bought a 4350 for my gaming computer ( I don't overclock). I am designing a computer for a church, and they want to run four screens. Does the processor matter in this case?
 


If you're worried about displays then your graphics card is what you want to look at. Your processor has very little to do with this. You'll either need a very powerful card that can run 4 displays (and cost a ton of money) or you can buy two cheaper cards that can run two each. That's the cheaper option and I would recommend that. As for processor, if you're putting the same thing on all screens the quad core should be fine. If you're running 4 separate programs at once I would go for the higher core count.
 


this is the video card that will be in the computer. Will it run them?
 


These types of cards are really designed for gaming, meaning one really good feed to one display. From what I'm getting you don't need exceptional quality, just quantity. I believe that card will run 4 displays (with some playing http://www.geforce.com/hardware/technology/surround/system-requirements) however it will be much more cost efficient to pick up two cheaper cards and run two displays like two of these https://pcpartpicker.com/part/msi-video-card-r72402gd3lp