VideoCardz has released a new leak benchmark comparison. In the cart they compare 3DMark benchmark result of GTX 1080, GTX TITAN X, GTX 980Ti, R9 Fury X, R9 Fury, GTX 980, R9 390X, R9 390 and lastly GTX 970 for a complete range of GPUs. All cards are running at their stock clock speed.
Although, they mention the clock speed of GTX 1080 clocks speed which between 1860 to 1886 MHz cause of GPU Boost 3.0 clock speeds are higher than stock.
They also share the screenshots from FireStrike benchmarks.