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Little confused on M2 terminology

Discussion in 'Storage Drives' started by Mercenary Keyboard Warrior, Jun 29, 2018.

  1. Mercenary Keyboard Warrior


    Joined: Aug 4, 2007

    Posts: 6,792

    Location: Wilds of suffolk

    I recently changed mobo and hadn't bothered with M2 before
    Something I had missed when i selected my new one was it only had 4 SATA ports and I needed 5

    Looking at my manual it says that as long as I get a pcie version and not a sata version of m2 then I keep all 4 sata ports, where as if I get a SSD version I lose SATA port 3, so thats clear a PCIe version for my boot drive should give me the other lanes I need back.

    What is confusing me is the mentions of x4 and x2 etc in some descriptions on the m2 2280 descriptions.

    Eg My mobo says 1 x M.2 connector (Socket 3, M key, type 2242/2260/2280 SATA and PCIe x2 SSD support)

    The key point is the PCIe x2
    Would this just be a limit on the max throughput, so for example the a Samsung 960 EVO that says PCI Express 3.0 x4 would run fine in the slot?

    Some seem to mention this and others not. So is this just higher performance versions of the tech?
  2. HoneyBadger

    Wise Guy

    Joined: Aug 2, 2016

    Posts: 2,092

    Location: Hoo, Kent

    What is your motherboard?

    It will either be that your board has PCIE x2 slots - as in, it can take 2x M.2 drives or it's saying the M.2 slot will run at PCIE2.0 x4 lanes Or PCIE3.0 2 lanes. (This last one is unlikely)
  3. Mercenary Keyboard Warrior


    Joined: Aug 4, 2007

    Posts: 6,792

    Location: Wilds of suffolk

    Motherboard is a Gigabyte H310M S2H
    The bit above is literally pasted from the manual.
    It definately got 1x M2 by the board layout, which matches the 1 x M.2

    The Socket 3 should mean from what I can tell from the standards that it can support full lanes.
    I wonder if it says x2 as maybe its using 2 channels to add to the 2x PCIe x1 slots to give 4 channels, maybe that made some internal wiring easy.

    As it says M key it should in theory be PCIe X4 from the standards, yet it mentions x2 which is what seems the anomoly.

    I was looking at a B&M keyed PCIe x2 anyway so shouldn't be an issue from what I can tell, I was just wondering about spending a little more for an EVO, but its pointless if the mobo is going to restrict to 2 lanes, I may was well buy a cheaper B&M slotted drive for this PC.

    The whole thing seems to be a minefield for poor labelling.

  4. Journey


    Joined: Oct 18, 2002

    Posts: 4,666

    Location: West Midlands

    The chipset only supports a 2-lane Gen 2. PCI-E M.2 slot, so you'll never get the full transfer speeds from the drives, however with NVMe and the faster drives it's the Q1T1 4k speeds that you want to be looking at i if it is an O/S drive and this slot will not bottleneck those as much, and you are talking <100 MB/s.

    Take a look at the ADATA SX8200 M.2 NVMe drive, it's be far and away the best value M.2 drive for using as a boot disk, and is faster than the Samsung 970 EVO (until the EVO get to 1TB), in everything other than sequential reads/writes, which you can't use anyhow.

    You need to use an NVMe drive, otther wise if you go for a SATA based M.2 drive, like the 860 EVO or Crucial MX500, SATA port 3 on your board will not work.

    Hope this helps a bit. :)