Help picking a GPU

It wasn't too long ago people told me 2GB vram was enough for higher-end cards (GTX 760/HD 7950/R9-280 and up). Very glad I went with a 7950 with 3GB vram instead of a GTX 760 with 2GB. Better to have a little overhead IMO. Of course if the price difference is unreasonable, then yeah, it's not that important. Running out of vram doesn't have the same game-stopping effect as running out of system ram, fortunately. 

Ok so I got the Asus r9 280x and now I have a noob question of connecting it. The Gpu has a 6pin and an 8pin connector. My psu has a free 8pin pci-e connector slot. Two cables came with my psu. One end is an 8pin and the other end has 2x 6+2 pin connectors. Also the gpu came with a 8pin to 2 6pin branch cable. The question is what end goes where?

In my experience, the higher vram cards paled in comparison to lower or same ammount of vram on newer cards. Of course things might change, but the decisive factor remains the application (of course large textures need ram, but a game that needs more than 2gb needs some serious optimization) and resolution.

For 1080p 4gb doesn't make sense. 3GB on the 280 is better because it's a better card, hardware-wise, but that's all on paper. In the real world you need to check benchmarks for your uses or you might be let down in some aspects (some cards perform better in some games programs).

GTX 760 is not a 7950 equivalent, maybe a 770/280.

Read the manual.

The 8 pin end goes in PSU, other 6+2 go in video card.

Managed to solve it myself about a minute after I posted the question. But honestly the manual was completely useless and didn't cover connections at all apart from display connections.