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.
There's little to choose between the factory overclocked GTX 980s, they're all mighty fast and are separated by the small differences in factory overclock. As the specification suggests, MSI's card slots in ahead of the Asus Strix and just behind Gigabyte's G1 Gaming.
3DMark Vantage provides a nod toward the memory-compression capabilities of the newer 900-series cards. Colour Fill rate, as illustrated above, is a marked improvement over previous-generation solutions.