http://www.hardwarepal.com/gigabyte-gtx-770-4gb-windforce-3x-benchmark-review/5/With our favorite overclocking tool MSI Afterburner we couldn’t get any where when it comes to overclocking. However, with EVGA Precision we managed to slightly bump up the voltage which enabled us to reach a stable 1280 MHz for GPU and 7484 MHz for memory which, we must state again is a very nice overclocking endeavor, especially if you take into a count that we were dealing with a cards voltage that has been locked in the BIOS. Now since the card was already overclocked to its maximum we knew we won’t get much out of it. +50 MHz (1280 MHz w/boost in total) and +233 MHz for memory making it 7484 MHz respectively is probably the maximum you can get from any GTX 770 unless your really really lucky.
As @cliffordcooley posted, the card is a great card with a great cooler, however they clock it near max already and it comes voltage locked via the bios. Your not going to get much more out of it sadly than it already comes at unless you get a lucky one that can go very far on the stock voltage.According to this write up, you wouldn't get much more out of the card. They mention the card is already clocked near its maximum.
Gigabyte GTX 770 4GB Windforce 3X Benchmark and Review - Page 5 of 18
made a mistake with my vram numbers - vram is +475, which is effectively an additional 950mhz, making the vram 7960mhz total.I have the second revision gigabyte gtx 770 4gb and it OCs very nicely.
currently at +50 core (~1280mhz), and +950 vram (just shy of 8ghz). stock voltage and custom fan profile (to keep it under 70C). rock solid, hasnt crashed once, still pushing the card.
ive read of a good number of people hitting 8ghz on vram. happy mine is practically there.
running an asrock mobo (some weird complicated name), i5 2500k at 4.8ghz, and an old pc power and cooling 610w psu.