TPU reports EVGA and K|ngp|n managed to overclock a GeForce GTX 680 to a whopping 1842MHz. Quite a nice bump from the stock clockspeed of 1006MHz.
Armed with NVIDIA GeForce GTX 680 graphics cards, augmented by EVGA EPower board, and PrecisionX software, the EVGA GTX 680 was able to crack the 1800 MHz core frequency mark, reaching 1842 MHz, powered by a core voltage of 1.212V. Interestingly, the memory clock offset wasn't tinkered with. The rest of the system consisted of a Core i7-3960X clocked at ~5.50 GHz. The bench was stable enough to score 14912 points at 3DMark 11 (performance preset). Compare this, to the R7970 Lightning clocked at 1800 MHz core, 7.70 GHz memory (370 GB/s bandwidth), with no additional soldering except plugging in the GPU Reactor, and a slower Core i7-3960X CPU (clocked at 5.00 GHz), which went on to score P15035.