For new GPU miners, I would recommend the following:
- If you plan to buy and use a single GPU, Tahiti based cards are currently the best option IMO. It means HD 7950 (currently hard to find), HD 7970, or R9 280. Curaçao, i.e. R9 270, is an interesting alternative for low budgets.
- If you plan to build multi-GPU rigs using PCI-e risers, i.e. you have many slots available, you will have the best value in terms of hash/watt and buying price with Bonaire chipset based cards, i.e. HD 7790 and R9 260
Note: "x" versions (R9 260x vs R9 260, R9 R280x vs R9 280) are generally more expensive for the same hashrate, as they each have the same number of shading units as their "non-x" counterpart.
is a good site where you can see what hashing rates different cards give. It kinda depends on how easy you can get hold of some cards.
7950 are good cheaper cards.
280x and 290x give great hashing rates.
Thank you very much. I'll go GPU hunting tomorrow. It's too late for bitcoins but there are some altcoins calling my name lol.