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.
AMD has historically done well in the synthetic 3DMark benchmark. One R9 295X2 provides impressive numbers, but adding a second increases performance by an additional 55 per cent. Still, the Sapphire duo remains a touch behind the three-way WaterForce.