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.

The fastest card in this high-end line-up, Radeon HD 7990, is about 33 per cent quicker than the single GTX 780. Adding another provides scaling of just over 60 per cent at the Extreme preset, which is more than enough to fly past the big-ass HD 7990.