The G1 shows (at least on Amazon) these specs:
Power by GeForce GTX 1080
Integrated with 8GB gddr5x 256bit Memory
Boost: 1860 MHz / base: 1721 MHz in OC mode
Boost: 1835 MHz / base: 1695 MHz in gaming mode
Support up to 8K Display @60Hz (Requires 2*dp1.3 connectors)
I'd imagine they're just playing it safe and you'd be able to overclock to 2000Mhz at least?