I heard the gtx 960 is like a boost up 660,760 aswell i don't like the 128bit .i wanna sli either the 770 or 960 and game either 1440p or 4K ,thanks the help
The performance difference between an NVIDIA Reference Design GeForce GTX 770 2GB card and an NVIDIA Reference Design GeForce GTX 960 2 GB Card is around 13% in favor of the GTX 770 2GB at 2560x1440 or 3840x2160 display resolution.
The R9 280 or 280x would be a much much much better option for you. The 280 is equal to the 960 for $40 less, and the 280x is roughly equal to the 770 for the same price as the 960. The 770 is EOL so they are really expensive unless you find a used one.
2GB is not enough to game comfortably at 1440p and would be pretty terrible at 4k. I've seen a GTX690 average 120fps in every game at 1080p, struggle at 1440p, and barely even run games at 4k.
Intel no longer makes the GTX770 so it's harder to find and overpriced when you do find it.
You can buy TWO R9 280 for $329
PCPartPicker part list: http://pcpartpicker.com/p/yknvRB
Price breakdown by merchant: http://pcpartpicker.com/p/yknvRB/by_merchant/
Video Card: XFX Radeon R9 280 3GB Double Dissipation Video Card (2-Way CrossFire) ($164.99 @ Newegg)
Video Card: XFX Radeon R9 280 3GB Double Dissipation Video Card (2-Way CrossFire) ($164.99 @ Newegg)
Total: $329.98
Two 280s would outperform a single GTX970 for the same price.
I'll tell you, either go with SLI GTX 770 4GB, NOT 2GB. Or side with R9 280x Crossfire. It's honestly for the best. Otherwise you're just sacrificing performance for Nvidia. So yes, go for the 770 4GB version or leave it.