I cant imagine that 780ti struggling too much, definitely handle any game without breaking a sweat.
But your i5 is gonna be working noticably harder, even with that higher clock speed.
That being said your CPU will probably be pushing 70-100% as the previous poster stated.
But I doubt you GPU will work nearly as hard.
3Gb memory on your video card gives you tons of breathing room and probably will be significantly less in usage. Unless your GPU picks up some of the load for your CPU.
Hard to give you exact numbers, but the software I listed before will be exactly what your looking for in those terms.