Blender wont open with dual gtx 1080 ti

HI, I have just installed a second gtx 1080ti. Blender will only open if one of them is disabled. Windows sees both just fine. I heard blender can use both cards for cycles. is that possible?
I tried the last 2 NVIDIA drivers. They are not SLI bridged.

Its an Alien ware Aurora R5
32 gig ram
850 watt power supply

yes, Blender can use both of them at the same time for CUDA rendering.

Which version of Blender and Windows version are you running?

I’m running OpenCL with 1 Vega and 1 RX480 (with 3 more to add) and have no issues rendering with two cards. Also running Windows 10.