3DMark
3DMark is the latest version of this hugely-popular synthetic benchmark. Making use of DX11 features such as tessellation, compute shaders and multi-threading, it provides modern-day results and is available as a free download.
An overclocked GTX 770 is a good match for the price-comparable Radeon HD 7970 GHz. PNY's card shades it in both resolutions though remains a step behind the higher-boosting Zotac. One aspect to note here is the significant performance difference between GTX 770 OC and stock GTX 780 - you'll see the gap close in real-world games.