So thank you for all of that information. It help a lot with what I needed to know. Although I am still a little confused on some things. I'm looking at graphic cards right now and these are the two I found that I think is what you two were talking about. Would you mind taking a look?
http://www.ebay.com/itm/MSI-GeForce-GTX-680-N680GTX-Lightning-DDR5-2GB-Graphics-Card-VGA-PCI-Ex-/331265827727?pt=PCC_Video_TV_Cards&hash=item4d20fb638f
http://www.ebay.com/itm/NVIDIA-GeForce-GTX-680-overclocked-4GB-Graphics-Cards-BRAND-NEW-/161373712986?pt=UK_Computing_Computer_Components_Graphics_Video_TV_Cards_TW&hash=item25929f725a
Also, would this graphics card be able to work on a macbook pro 2013? And would it help it run shadows smoothly? Or would I be better off buying a refurbished computer?