Hey guys. I am thinking to turn my desktop, ASUS Rog Tytan CG8480 into a rig. I really don't care about the ROI so my questions ar based on the effiency. I currently own a 4gb gtx660 card, which is actually old. Seeing 2k to 2.5k hashrates. I own a laptop with GTX760M and it gives around the same hash. Using ccminer. My motherboard does accept 4 more PCI-E 2.0 slots and after my research I concluded that GTX 750 Ti cards can work with 2.0 slots. My PSU is 750 watt corsair, so I don't think voltage would be a problem if I add 2 cards. The price of Nvidia GTX 750 is my country is around 170 dollars (THE OC ONE). What hashrate would I earn by adding 2 new 750 Ti OC's? My hash is 4000khs right now, what would be the sum with new cards? I use completely free electricity. Living at dorms. Please help me if 750 Ti's are my best choices. R290's are around 390 dollars here and my 2.0 slots wont probably support their watt needs.