11-22-2016, 08:57 PM
If you search the forums you'd know that this is a known issue with Windows. Some people have gotten 7 GPUs to work with Windows after modifying some driver files, but I don't know anyone who has gotten 8 or more to work. Though I've heard this may have changed with Windows Server 2016, I have not confirmed because I'd never even consider running Windows on such a system.