FunkyKit posted a review on the Introducing the New EVGA GeForce GTX 970 SSC ? 140MHz Faster, 6% Cooler GPU, 33% More GPU Power A quote from the article:

The new generation of EVGA GeForce GTX 970 has arrived with the SSC. This enhanced model offers improved cooling, double BIOS support, new display output configuration, and 6 power phases for robust overclocking support. These new cards also feature EVGA ACX 2.0 cooling that features optimised swept fan blades, double ball bearings, and an extreme low power motor. The EVGA ACX 2.0 cooler offers more air flow, with less power, unlocking additional power for the GPU.

 Introducing the New EVGA GeForce GTX 970 SSC ? 140MHz Faster, 6% Cooler GPU, 33% More GPU Power @ FunkyKit