There are people with big big big gpu farms:

https://lh3.googleusercontent.com/-uDTDLbEEPDQ/ToHFXnN3xgI/AAAAAAAAAwg/RQNePkHKrI4/s720/IMG_0141.JPG

http://bbsimg.ngfiles.com/4/23936000/ngbbs4fa1e4a7883fa.jpg

http://25.media.tumblr.com/tumblr_m5oir7kc1k1qfy0bho1_500.jpg

http://i42.tinypic.com/16583p.jpg

http://24.media.tumblr.com/tumblr_m3sp4m5Oda1qfy0bho1_500.jpg

http://4.bp.blogspot.com/-wpl0-qFnVuQ/UFOPru3GQbI/AAAAAAAAAZE/jIkvUbEw5T0/s320/bitcoin_mining_setup.jpeg