A rumor popped up that AMD may be working on at least three graphics cards based on its Vega 10. The origin of the rumor is a set of 3DMark Time Spy benchmark scores, which seem to reveal three different SKUs with varying performance levels.
The three device IDs are the 687F:C1, 687F:C2, and 687F:C3 and the benchmark database entries suggest all three models feature 8GB HBM2.
I would take this information with a grain of salt but the scores suggest the slowest model could be faster than the GeForce GTX 1070, while the fastest Radeon RX Vega card may offer performance similar to NVIDIA's GeForce GTX 1080 Ti. It's hard to say as some of the scores are all over the place.