Honestly, it was probably the easiest fresh OS install I've ever done. Certainly not what I was expecting given the limited information I could find, but I've always run into some kind of issue when installing Windows. This was the first time where everything went smoothly and I didn't have to chase gremlins around. No custom BIOS was needed. I do have the latest BIOS, but since the board is so old I think the BIOS is like 5 years old. I did a completely clean install - no cloning. As I mentioned in my earlier post the only BIOS setting I messed around with was the "Addon ROM Display Mode" and I'm not even sure if that was necessary. Samsung's consumer NVME drives (the 950 Pro's) use a controller chip that is compatible with legacy BIOS systems. This means you shouldn't need UEFI to use it as a boot drive. I know there are at least one or two other people on other forums who were successful using the 950 Pro as a boot drive on X58. I haven't read about anyone who wasn't able to get it working, but that might just be due to the small number of people still running an X58 system.