sam_p_lay :
+1 to everything said here except the Playstation remark. Skylake may be yet another microscopic advance from Intel, but it's probably the soonest potentially-worthwhile upgrade.
What will happen with Your current configuration is that since gtx 780 is based on a GK110 architecture it will have 8 of the 32 HYperQ lanes open to talk between the ram and your cpu, since Your CPu has no matter what the clock is only 8 mb of cache, as a result the card will run very cool and deploy a better spread of computation with SMX, on the other hand Your CPU having such a big bulk of information ready to be processed will run super hot and at top clocks engaging all the hyperthreading and boosts.
If You will cool Your CPU the card will still perform excellent and cool and silent with plenty of extra power that Your system cannot anyhow process and You will be able to use a little more of all the power that the GPU can offer.
HOWEVER game developers still are not in photorealistic graphics quality, veyr few games have now cute graphics builds textures and materials,so from mY point of view investing in a high end gaming card today is not justified since these kind of cards are designed fur MUCH higher resolutions much higher polys much more sophisticated material renders in the game engine, so spending 700 dollars for 200 dollars of games that You will buy in the next couple of years is not a justified investment.
Thus a playstation is much better option for gaming on the long run, until there will be a decent basket of games available that run photorealistic graphic content.Then 5 years from now a GTX 780 will still be a very good GPU, proper, and properly milked during the game,to its full potential and worth the investment.
it is all about getting just above 30 FPS in ultra settings since the human eye cannot perceive more than that....for a acceptable fluent experience instead 20 fps.
so choose any card that will give You at least 30 FPS in full ultra in the games you want to buy.....unless you positive you will keep ur current rig for 1 year only.