Hello, Im planning to get 2,1 Mac Pro as my "workstation". I want instal El Capitan and Windows 7/10 64bit on two SSD + 2 TB Hard Drive. Mac comes with HD 5770 which i want upgrade to GTX 960/70 or maybe GTX 780 idk. So is HD5770 gonna work with El Capitan and Windows 10? This 5770 is flashed i think , it dont look like normal mac hd5770 cos it dont have 2 mini dp just normal ports. Seller said he got bootscreen so i think its flashed.