Honestly at higher resolutions, such as 1440p, it is wiser to invest your money towards a strong GPU with lots of VRam. I have the same CPU as you, and for me it is holding steady preformence, especially because of newer games using its 6 cores. In my opinion, it is not worth the cost of getting a new cpu, and with that H80, you can easily get 4GHz out of that beast. But I stongly advice a powerful GPU, such as the 780, but remember that at such high resolutions you will want to increase texture res, which needs a big framebuffer, so get a card with 3gb or more. Honestly tho, don't stress too much about bottlenecking, the CPU still has some OC headroom, and it's number of cores is keeping it in the game. The only games that it really holds back my crossfire setup, are Stalker, and Splinter Cell.
Regards