jgt1942 wrote: I'm considering the Samsung 950 PRO -Series 512GB PCI SSD but I don't know if the  990FX Extreme9  has support for the M.2 four lanes. If not, can I use the Lycom DT-120 M.2 PCIe to PCIe 3.0 x4 Adapter and get full function from the SSD? +1close < id="ezPreviewPO" border="0" scrolling="yes" style="width: 100%; height: 90%">  closepinpinsearchminimizeforwardbackViewTextEmailzoomoutzoominzoomin < id="eztxtSearch" ="text" style="width: 120px; font-size: 8pt; -webkit-border-radius: 8px; border: 2px solid #ddd; padding-right: 4px; padding-left: 4px;" title="enter search term and click desired search engine" vk_176a0="subscribed"> < id="ezPreview" border="0" scrolling="yes" style="width: 100%; height: 90%">

1. No M.2 slot on this board.
2. This board only supports a PCIe 2.0 interface, not the PCIe 3.0 interface that the 950 Pro requires for its full speed. The Lycom DT-120 adapter is PCIe 3.0 compliant, but it does not supply PCIe 3.0 lanes to a mother board.  A 950 Pro can work with a PCIe 2.0 interface, but not at its full speed potential.
3. This board does not have a UEFI/BIOS update to support NVMe. That limits the use of an NVMe SSD to a storage drive, not as the OS/Windows drive.

So the answer to your main question is no, you cannot use the Lycom adapter to get the full function from a Samsung 950 Pro.

The few 990FX boards that have an M.2 slot have a PCIe 2.0 x2 interface, rather than the PCIe 3.0 x4 interface required by the 950 Pro, or Intel 750. That interface would take a 950 Pro down to less than 1/2 its specified performance.

You would do somewhat better with a PCIe 2.0 x4 interface and the DT-120 card, but it would only be about 1/2 the specified performance.

Hopefully the next AMD processor generation (Zen) will have PCIe 3.0 support in the CPU and/or chipset, as FM2+ boards/processors have.