BeltFed wrote:
It would be worth taking a look at this article.

http://www.bit-tech.net/hardware/storage/2015/11/11/samsung-ssd-950-pro-review/1

"The problem turned out to be something as simple as our overclock settings. We use Corsair Vengeance LPX DDR4 modules rated at 2,800MHz, and we were using their built in XMP profile for our system's overclock. However, this automatically sets the base clock to 125MHz, which is a requirement when using high frequency memory (i.e. above 2,666MHz) on X99. However, this also affects the speed of other parts of the CPU, not just the cores, and one of those parts is the onboard PCI-E Gen 3.0 controller. In turn, in order to maintain PCI-E stability at this clock, our motherboard was downgrading the PCI-E interfaces to Gen 2.0. You can force the graphics slots back to Gen 3.0, but there's no such option for the M.2 slot, which makes sense since storage devices require perfect stability. We have not been able to confirm exactly how other motherboard manufacturers handle the situation, but it's probably safest to stick to 2,666MHz DDR4 on X99 when using a PCI-E 3.0 storage device. It should also not be a problem on Z170, where the PCI-E controller's clock is separate to the CPU BCLK. "

Chino wrote:
You'd need to use one of those M.2 to PCIe adapter for your Samsung 950 Pro to make it work.

Halodies wrote:
I'm going to upgrade my processor, maybe the new one will have more lanes 😄

BeltFed wrote:
Just keep in mind that the article I posted was using a 5960X, I dont think you can upgrade any more from there, and they still had the issue with the XMP profile setting the BCLK to 125 and downgrading M.2. You either downclock your RAM down to 2666MHz or 2400Mhz with a BCLK of 100 to allow M.2 to work at full capacity, or like Chino said, you could try using a M.2 PCIe adapter card on that 4th PCIe graphics slot, and force it back to Gen 3.0, since there isnt an option to force M.2 back to PCIe 3.0. With this last method you should be able to keep your XMP profile, emphasis on "should".

I do not know if there is any performance hit by using a PCIe adapter card. Maybe someone else can chime in on that.

LiveOrDie wrote:
Don't take this the wrong way but you don't have any understanding of the mater in hand, please read my post here before giving bad pointers to other people.

http://rog.asus.com/forum/showthread.php?53091-Rampage-V-Extreme-M-2-Setup-And-Windows-Installation-...

gene-iv-ocz-revo3-240 wrote:
I have the 950 Pro and can boot fine with it in the M.2 slot with a raid0 drive. It's possible the boot order changed in the bios and you need to switch it.

Also I installed Windows10 on the 950PRO in UEFI bios mode I have not tried any other method.