I’m looking into purchasing a refurbed Optiplex 7040 but I’m fairly unfamiliar with them. 

Overall, the specs look pretty good with an Intel i7 3.2Ghz processor, 16GB DDR4 RAM and 1TB SSD but the graphics card is sub-par; Intel HD Graphics 530.

Is it possible to upgrade the graphics card on one of these units? Or add a designated graphics card?