GTX 660 sli vs R9 290

Solution
One R9 290, it'll max out anything at 1080p and is an extreme GPU, though the GTX 660's in SLI will perform better, not all games support SLI, making those games only use a single GTX 660. Also for games that do, you will experience micro-stuttering and small lag spaces during gameplay, though it all isn't that bad, your best going for a single GPU that can handle a good resolution. I opt for a R9 290, Make sure it is either of these though;

ASUS DCUII / Sapphire Tri-X / Gigabyte Windforce 3X / MSI Twin Frozr, never buy the stock cooled model.
One R9 290, it'll max out anything at 1080p and is an extreme GPU, though the GTX 660's in SLI will perform better, not all games support SLI, making those games only use a single GTX 660. Also for games that do, you will experience micro-stuttering and small lag spaces during gameplay, though it all isn't that bad, your best going for a single GPU that can handle a good resolution. I opt for a R9 290, Make sure it is either of these though;

ASUS DCUII / Sapphire Tri-X / Gigabyte Windforce 3X / MSI Twin Frozr, never buy the stock cooled model.
 
Solution