780 vs Titan vs K40

Thanks to the help of some friends i was able to run the parallel dijkstra implementation on some different hardware all based on the kepler architecture.

Map	K40	780	Titan
32x32	8.341714	8.057811	8.645273
64x64	16.37582	15.68679	15.75337
128x128	32.52248	28.07575	28.05111
256x256	65.31222	54.97772	55.49513
512x512	140.5209	119.8173	119.7446
1024x1024	399.7442	355.7623	338.7315
2048x2048	1745.794	1589.061	1449.108