I was not sure about the fastest, but the Intel RST drivers are definitely stable and fairly recently updated.
Final thoughts on my little project of running two Samsung SM961 NVMe drives in RAID 0.
Let me say this straight out. This is a great setup if you are a benchmarker on a budget. I love the high benchmark scores, but after having the single Samsung 960 Pro as a boot drive and now the twin SM961 drives that scores higher in most disk benchmarks (although not all); honestly, I can't tell the difference between them in real world usage. And, the average fellow probably don't really need either setup just to surf the net and check email.
I do not hesitate to recommend any of the Samsung drives I currently have in my fleet: not only the M.2 drives, but also my faithful SATA 2.5" Samsung 850 EVO. The time has not yet come for the NVMe RAID 0, although about the price... let me say again, I did build this RAID 0 for less than the price of a single 960 Pro. Striped drives are all about performance. There is an old saying in the car hotrod culture: cheap, fast, and reliable--pick two. I think it mostly applies with computers too. But, two SM961 drives might be the exception to the rule (although only time will tell on reliability).
Seems pretty clear there is a bottleneck in drive speed at about 4 GT/s on my current setup. Not sure if I had one of the drives in PCIe slot adapters if that would help or not? I think the PCIe lanes on the current motherboards are too congested (CPU uses them and the vid card(s) of course), but each new motherboard version seems to get better. Of course they better because PCIe 4.0 is ready to roll out soon and PCIe 5.0 should be ready by 2019. The raw bit rate max for 4.0 will be 16 GT/s and for 5.0 the goal is to double that amount (currently 3.0 is 8 GT/s).