Z170 Extreme6(+) and Samsung 950 Pro NVMe SSD

I boot my 950 Pro from my Z170 Extreme7+ fine, and you can from your Z170 Extreme6+ too.

My board does not have an NVMe configuration screen or is shown among the list of SATA drives. Of course, it really is not a SATA drive, it is an NVMe drive. It appears in the System Browser screen and is visible in Windows. Given my board, that is the norm for NVMe drives. Don't expect a 950 Pro to act the same as SATA drives.

Do you have the Samsung NVMe driver installed? That is not required for booting or installing Windows.

One thing you need to do is find the CSM option at the bottom of the Boot screen. CSM is normally enabled. Find the sub-option Launch Storage OpROM Policy, and set it to UEFI Only. Of course save and exit. You'll need to maintain that setting of Launch Storage OpROM Policy, such as after a UEFI/BIOS clear or UEFI update.

You still may not see the 950 Pro in the boot list, but don't worry. I assume you did not install Windows 10 with Launch Storage OpROM Policy set to UEFI Only on your current Win 10 installation, which will be MBR partitioned. Cloning it to the 950 Pro won't work in that configuration.

You must install Windows 10 on the 950 Pro with Launch Storage OpROM Policy set to UEFI Only. The Win 10 installation program will see the 950 Pro, and allow Windows to format it. You will of course boot from your Win 10 installation media. During the installation, ONLY have the 950 Pro powered on, NO other drives should be powered on during the installation.

When the Win 10 installation is complete, you'll find an entry in the boot list of "Windows Boot Manager: Samsung 950 Pro".

Welcome to the world of NVMe SSDs. They are not SATA drives so don't expect them to be listed with them or treated the same.