Should I buy Dell XPS 13 or XPS 15

[Tauxi]

Dell outlet has 500$ off and 5% student discount. There are 2 configuration at same 882$ below:
Xps15, i5, 4k, 6 cell battery
Xps 13, i7, 2k screen, 4 cell battery

Which one should i buy, i only play Fifa 16-17, working with matlab and hope battery lasts for 6hrs.

 

[Maziar]

I recommend going with XPS 15. I assume it's got a better GPU as well ?

 

[Aydin7]

I went for xps 15 with 526gb ssd and 1080 screen for longer battery

 

[velo3100]

Go with the 15 inch, it will make a difference in matlab if you are dealing with complex matrices