Twin 670s should be a very acceptable solution. I would expect it to be significantly cheaper than selling one and buying say a 780 Ti....it will also be faster.
You will need 750 watts, more if CPU / GPUs overclocked, as well as 2 PCI-E slots.
the prices of the 4gb ones are like 270 cheapest think i should buy another ? or sell the one i have for 180 (or something) and put 180 and 270 towards a new card ? or or sell the one i have and buy 2 2gb 670 cards lol
Well that is a bit expensive, but you can't probably get more power by selling the old one and investing in a new card/SLI setup, getting the second 4GB card might be your best option.
Its always best to get the exact same exact card if for no other reason than both companies will refuse to provide tech support for the SLI configuration. Of course cards of different speed or memory will downclock to the lowest common denominator.
915 MHz card + 950 Mhz card = two 915 Mhz cards in SLI
2 Gb + 4 Gb card = two 2Gb cards in SLI
ok thanks mate so with that said think i would be better to get a EVGA 2gb version ? and i thought u had to get a 4gb i dont know a 2gb would work with a 4gb. Lowering it down to 2gb wont bother me i only use 1 screen anyway
I would think that there are a lot of used cards for sale right now..... but a quick peek showed wide range of pricing from $71 to $400. Will depend on what model. I wouldn't be surprised if you could sell your single 4Gb model for $300 and get two 2 GB for $200 each