Should I install NVMe M.2 ssd in M.2 socket or in PCIe slot using PCIe adapter?

Question

I have an asrock z170 pro4s motherboard and I need help with understanding where I should put the samsung 960 evo.
http://www.asrock.com/mb/Intel/Z170%20Pro4S/index.us.asp http://www.microcenter.com/product/471502/960_EVO_Series_250GB_NVMe_M2_Internal_SSD

I will install windows 10 and ubuntu on the samsung 960 evo and boot from this device.

Which slot will give me the faster speed, putting the ssd in the M.2 slot or using a PCIe adapter and putting it in the second PCIe slot, this is a PCIe express x4 lane because my gpu is in the PCIe express x16 slot.

If I put the ssd in the PCIe slot, will it reduce the speed of my gpu?

My motherboard manual says "If the Ultra M.2 Socket is occupied by a SATA-type M.2 device, SATA3_0 and SATA3_1 will be disabled."
I shouldn't have to worry about those two being disabled because the samsung 960 evo is an NVMe M.2 device, not SATA right?

Answer 1

You should put it in the m.2 nvme Slot. The 960 Evo uses at maximum 4 PCIe lanes, and it is debatable whether a GPU actually performs significantly better using 8 or 16 Lanes. This means that slowing your GPU by using the PCIe m.2 is unlikely. I would advise against a PCIe card for your 960 Evo if your motherboard already has a specific slot for your NVMe drive.

Depending on the number of lanes that your CPU (what model?) supports, I would even still use the M.2 slot.

The only issue with the SATA is that if you put a M.2 SATA drive in the m.2 SATA (not the PCIe x4) slot, you will lose access to two SATA ports, port 0 and port 1, as specified in your manual.

Your motherboard has 6 SATA ports, so you would only have access to four, if you are using more than four extra drives as well as the m.2 drive, then this is where it would become a problem.

The 960 Evo isnt a SATA drive, it is an NVMe device, so the SATA information above is just for reference