Re: new rig mostly for gaming
Are these pre-built rigs? If so, how much are they?
Would you consider building your own?
And if not, then the second system would be my choice as it has the better graphics card. And with the motherboard choices, at this point, most of the P55 motherboards perform similarly to each other. The only main difference is features. I would go for the ASUS. In my opinion, it's better supported and usually the better overclocker.
If you can switch out the HD 5850 in the first rig for a an HD 5870, then go for that.
3770K | ASUS STRIX GTX 1080 | DDR3-1600 16GB | CORSAIR 650D | CORSAIR HX 850W | CORSAIR H100 | SOUND BLASTER Z | ASROCK EXTREME4 GEN3