Sapphire Radeon R7 260X vs GeForce GTX 560

R7 260X without a doubt. It's on par with a 750Ti and has a more modern architecture supporting more DX11 and DX12 features. It's more powerful and consumes less energy.
 


I had the same conversation with a friend, I know the Raden is more powerfull (dont really care about energy usage) but the Geforce has +50% more memory bus , some ppl say that the new GPUs dont need the memory bus no more.
cant really decide.

 
The R7 260X has slightly lower memory bandwidth (104 GB/s vs 128 GB/s of the GTX 560), however it has better performance anyway because of its shaders, higher speed and an architecture that is geared towards both DX11 and DX12.

Memory bandwidth is important, but sometimes other things make up for it.