Not bad! How about this GPU:http://www.newegg.com/Product/Product.aspx?Item=N82E16814133526&cm_re=pny_780_oc-_-14-133-526-_-Product
I have it and it's amazing. The clock rates/sound levels of this card blew me away with both reviews and owning it. Did you notice $660 after rebates?! I hit 1288mhz for hours all day everyday with a slight OC after the stock OC.
A 6gb 780 is still slower than a 3gb 780ti @ 4k just to let you know. I actually think these OC cards still do better than titan black @ 4k. OC a titan black and you may finally have an advantage I just haven't seen anything substantial to prove otherwise. Please don't go 4k gaming, it needs 2GPUs for maxing. 2k/1080p with all eye candy on, and never dipping down below 60 fps (I think that number should go down to 40FPS with G-sync) is far more amazing than 4k medium/high settings.
With the money you save get the i7 4770k. I used have Hyper-threading off for the first the few years I had my i7 2600 because I would get better benchmarks with the higher per core performance of HT off (which is why most people recommended the i5), but ever since the 337.5 driver and up I get better benchmarks with HT on. I didn't believe it until I saw it.
Edit: You may be able to scrap the thermal paste as these cards run very cool. In less someone can show be better benchmarks because of it on a 780ti.