Sorry if it has already been answered but I have 2 questions:

I'm currently mining on win7 with a geforce 1080 and it works great.
I'm building a rig with somewhere between 8 and 12 gtx 1080 ti cards.

1.Is there a difference between the OSes?
For example is there any benefit if instead of win7 I'm switching to ubuntu or win10?

2.If I stay on win7: How many gpus are supported?
I tried searching for an answer but all I get are mixed answers depending on how old the threads are.

Would really appreciate it if somebody could help me out!