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M.2 SSD PCIE 3.0x4 vs 2.0x4

I am planning an upgrade to my PC, and I plan on setting up a M.2 SSD for the boot drive. I have selected a Z97 Mobo with the M.2 slot. There seems to only be two SSDs on the market around the $200 mark, the Samsung 950 Pro which utilizes PCIE 3.0x4 and the Hyperx Predator which utilizes PCIE 2.0x4.

I have read up as much as I can find on these new M.2 based SSDs and I have found a lot of conflicting information. Some claim their speeds are limited through the SATA bus, where others claim they will limit your PCIE bandwidth of your video cards. However, it appears it may depend on the particular card you buy?
I've seen that most of the M.2 SSDs on Newegg, although they say they're M.2, are still SATA based cards, and in the technical specs of the Mobo it even says that SATA 5 and 6 will be disabled when the M.2 is in use.
These two cards linked above stand out in terms of transfer speeds from all the SATA based M.2 SSDs I found on Newegg. This must be because they use the PCIE bus, and are completely separate of the SATA bus.
Does that mean (if I have two video cards in Xfire) that it will limit them to 8x and 4x respectively if I were to use the Samsung SSD which uses PCIE 3.0x4?
If so, does that mean it would be better to go with the HyperX which uses PCIE 2.0x4, which would utilize all 4 of the PCIE 2.0x1 slots, which would provide the SSD a dedicated channel to the CPU as long as I don't use the PCIE 2.0x1 slots? This way it should allow the two video cards to each utilize the full 8x on the PCIE 3.0, right?

Please correct me if my understanding of any of this is incorrect, and give me your advice on how to get the best performance out of a M.2 SSD on this Mobo while running Xfire, Thanks.


For your reference, these are the storage specs of this Z97 Mobo:
Storage Devices:
SATA 6Gb/s
6 x SATA 6Gb/s ports (SATA1~6)
M.2
1x M.2 port*
M.2 port supports M.2 SATA 6Gb/s module
M.2 port supports M.2 PCIe module up to 10Gb/s speed**
M.2 port supports 4.2cm/ 6cm/ 8cm length module

* The SATA5 and SATA6 ports will be unavailable when installing a module in the M.2 port.
** M.2 PCIe interface only supports UEFI option ROM, NOT support legacy option ROM.
SATA RAID
0/1/5/10
13 answers Last reply Best Answer
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  1. I just thought of something:
    Are the PCI-E 2.0 slots separate from the 3.0 slots?
    In other words: say I had 2 PCI-E 3.0 video cards running 8x/8x, and I used an SSD on the m.2 slot running PCI-E 2.0 in 4x.
    Would I then be running 8x/8x in 3.0 and 4x in 2.0? or would I be running 8x/4x/4x and there is no separation between the two versions of PCI-E?
  2. interesting question - i'd like to know as well - hope you don't mind if i watch this thread

    and fwiw, i'd go with the samsung 950 PRO - just to future proof yourself - the 3.0 is backwards compatible with 2.0 and even 1.0, it's just that 2.0 is going to hold back that SSD's speed, but to be frank, i doubt you'll notice it. Even the leap to 2.0 speeds will be incredible. When i installed my xp941 (first gen PCIe SSD), i couldn't believe the difference from my sata ssd - and that xp941 runs about 1/2 the speed of the 950 pro

    hope that helps some
  3. Best answer
    The vast majority of Z87, Z97, Z107, and X99 motherboards can support some type of M.2 solid state drive but there may be some restrictions. M.2 operation requires the use of several PCIe 3.0 channels or PCIe 2.0 channels to transmit and receive data. Graphic cards and sound cards also use PCIe channels.

    You already know that the Z97 motherboard has one M.2 port. The problem is there are several M.2 variations. Here are the current possibilities:

    M.2 3.0 x 4 - State of the art M.2 ssd that uses 4 PCIe 3.0 channels for proper operation. The M.2 port on the motherboard is sometimes referred to as an Ultra M.2 port. It is the appropriate port for the Samsung 950 Pro ssd.

    There are other M.2 ssd's that either use PCIe 2.0 or use fewer PCIe channels:

    M.2 2.0 x 4
    M.2 2.0 x 2
    M.2 SATA 3

    You will need to check your motherboard manual or the company web site to determine if the M.2 port can support an M.2 3.0 x 4 ssd like the 950 Pro. A lot of the Z87 and Z97 motherboards had M.2 ports for M.2 2.0 x 2 ssd's that would not fully support an M.2 3.0 x 4 ssd. With the exception of ASRock, the other motherboard manufacturers did not do a very good job of fully identifying the M.2 ports. You will have to find a little more information about the M.2 port on your motherboard. Hopefully the information is in the owners manual or the manufacturers web site.

    The addition of M.2 ports on the the motherboard required the use of addtional PCIe channels. Unfortunately Intel resisted adding chipset support for additional PCIe channels until recently. The lack of a sufficient number of PCIe channels resulted in some awkward solutions:

    Some motherboards reduced the number of channels available to graphic cards. The cards might be reduced from PCIe 3.0 x 16 down to PCIe 3.0 x 8. Graphic card performance is reduced by about 5%. That is not a terrible hit in performance.

    Some motherboards reduce the number of SATA 3 ports that are available. For example,the MSI Z107 Titanium motherboard has two M.2 3.0 x 4 ports. If I install a 950 Pro in each port, then all of the standard SATA ports are disabled except for two ports. The M.2 ports do not reduce the performance of graphic cards

    Some high end motherboards add an expensive PLX chip to handle M.2 ssd's. An example would be the ASRock Z97 Extreme9 motherboard. The PLX provides direct data transmission between the M.2 ssd's and the cpu. It is actually possible to run two graphic cards in SLI at PCIe 3.0 x 16 each and still be able to run two M.2 ssd's.

    The Samsung 950 Pro uses the new NVMe protocol instead of AHCI. A motherboard would have to have a UEFI BIOS, an Intel chipset, and a Microsoft Windows operating system that support the NVMe protocol. You would have to do the following:

    Check for any BIOS updates. Sometimes the updates include new and improved support for the NVMe protocol.

    Check for any Intel chipset upates. Sometimes the updates include new and improved support for the NVMe protocol.

    Windows 7, 8, and 10 can support the NVMe protocol. Again you will have to check for updates or fixes that can improve NVMe support. NVMe is new so things could get a little complicated.

    Finally Samsung has issued their own NVMe driver for the 950 Pro. Reviews and articles indicate the Samsung NVMe driver is better than the Windows NVme drivers.

    Some modern motherboards still provide a PCIe 2.0 slot. That does not mean you should purchase a PCIE 2.0 ssd or an M.2 ssd with an adapter card. M.2 3.0 x 4 ssds are backwards compatible.

    It might be confusing but for all practical purposes it is just a matter of checking requirements and specifications.
  4. Damn I should have refreshed the thread before I posted that answer, you basically said the same thing. But I don't see any mention of a special M.2 controller on the Extreme9, it just has the v3 M.2 socket, same as the Extreme6.

    Ahah, I finally found on the MSI website, the m.2 slot supports only PCI-E 2.0 x2.

    On to this Motherboard:
    ASRock Z97 Extreme6
    Not only does it's specs on Newegg solve almost all of my questions in this thread, it is also a pretty bad ass board.
    It has 2 M.1 slots, M2_1 is a v3 capable of 4x (32gb/s), and M2_2 is a v2 capable of 2x (either sata 6gb/s or PCI-E 10gb/s)
    So as it turns out, this is the only board on the market to support the new 4x SSDs.
    It also will support SATA Express when it comes out, which shares lanes with SATA_4, SATA_5, and the M2_2 slot.
    This also answered my question about how lanes are shared between PCI-E 2.0, 3.0, and the M.2 slots.
    It seems from what ASRock is telling us with this technical data, that there are basically 16 total lanes for the PCI-E bus.
    Each slot is labeled by its possible total variation of x (x16, x4, x1 etc.) When a card is used, it will automatically use the maximum bandwidth for that slot. When a second card is used in an other slot, the bandwidth will be split between the two. When a card is used in the M2_1 slot, the bandwidth is split once more, in this scenario resulting in an 8x4x4 split (PCIE2, PCIE4, M2_1)
    Quick labeling of the PCI-E slots:
    M2_1 - M.1 v3 x4
    M2_2 - M.1 v2 x2
    PCIE1 - 2.0 x1
    PCIE2 - 3.0 x16
    PCIE3 - 2.0 x1
    PCIE4 - 3.0 x16
    PCIE5 - 2.0 x16 (limited to 2x?)

    Expansion Slots
    PCI Express 3.0 x16
    2 x PCI Express 3.0 x16 Slots (PCIE2/PCIE4: single at x16 (PCIE2); dual at x8 (PCIE2) / x8 (PCIE4))
    PCI Express 2.0 x16
    1 x PCI Express 2.0 x16 slot (PCIE5: x2 mode)
    PCI Express x1
    2 x PCI Express 2.0 x1 Slots
    * If M2_1 slot is occupied, PCIE2 slot will run at x8 mode, and PCIE4 slot will run at x4 mode.
    Mini Card Slots
    1 x mini-PCI Express Slot
    * mini-PCI Express slot is shared with PCIE3 slot.

    Storage Devices
    The M.2 Socket (M2_2), SATA3_4, SATA3_5 and SATA Express share lanes. If either one of them is in use, the others will be disabled.
    M.2
    1 x Ultra M.2 Socket (M2_1), supports M.2 PCI Express module up to Gen3 x4 (32 Gb/s)
    1 x M.2_SSD (NGFF) Socket 3 (M2_2), supports M.2 SATA3 6.0 Gb/s module and M.2 PCI Express module up to Gen2 x2 (10 Gb/s)

    I wish I had seen this Mobo first, it gives excellent detail to how all the expansion slots and SATA bus work in terms of lane sharing, and compatibility with one another.

    So the decision as to which SSD to go with, as it turns out, is a no-brainer. It has to be the Samsung with it's higher speeds due to the PCI-E 3.0 x4 compatibility.
  5. The PLX installed on the ASRock Z97 Extreme9 is mentioned in technical reviews.

    I maintain an ssd database that is listed in a sticky at the very top of this forum section. Here is the link:

    http://www.johnnylucky.org/data-storage/ssd-database.html

    The ssd's are categorized by interface from PCIe 3.0 x 4 all the way down to mSATA. For each model there are links to technical reviews. The reviews are divided into English Language reviews and reviews in many other languages.
  6. Awesome, thanks for the great resource.
  7. Hi everyone! I bought one MB GA-Z170X-Gaming 7. In the specifications, it's written: "2 x M.2 Socket 3 connectors (Socket 3, M key, type 2242/2260/2280 SATA & PCIe x4/x2/x1 SSD support)". I'd like to buy one SSD Samsung 960 EVO of 1TB. In the specifications, it's written, about the interface: "PCIe 3.0 x4, NVMe 1.2 (partial)". I will have any trouble with this combination? It would be interesting I buy an adapter for the SSD? Obs.: I have a Zotac GTX 1080 AMP EXTREME GPU. Thanks!
  8. Gustavo do Valle said:
    Hi everyone! I bought one MB GA-Z170X-Gaming 7. In the specifications, it's written: "2 x M.2 Socket 3 connectors (Socket 3, M key, type 2242/2260/2280 SATA & PCIe x4/x2/x1 SSD support)". I'd like to buy one SSD Samsung 960 EVO of 1TB. In the specifications, it's written, about the interface: "PCIe 3.0 x4, NVMe 1.2 (partial)". I will have any trouble with this combination? It would be interesting I buy an adapter for the SSD? Obs.: I have a Zotac GTX 1080 AMP EXTREME GPU. Thanks!


    I can't tell if that mobo will support NVMe, but maybe the SSD means partial NVMe so it is also compatible with SATA or PCIE?
    Not really sure on that one, I ended up buying a Sabertooth 990FX, with no M.2 ports, and just bought a HHHL adapter for my SSD because at the time, the good AMD socket boards were hard to come by with M.2 slots.
  9. Gustavo do Valle said:
    Hi everyone! I bought one MB GA-Z170X-Gaming 7. In the specifications, it's written: "2 x M.2 Socket 3 connectors (Socket 3, M key, type 2242/2260/2280 SATA & PCIe x4/x2/x1 SSD support)". I'd like to buy one SSD Samsung 960 EVO of 1TB. In the specifications, it's written, about the interface: "PCIe 3.0 x4, NVMe 1.2 (partial)". I will have any trouble with this combination? It would be interesting I buy an adapter for the SSD? Obs.: I have a Zotac GTX 1080 AMP EXTREME GPU. Thanks!

    this obviously supported,
    because the motherboard has written PCie 3.0 x4 SSD support,
    that means in the M2 slot of the motherboard , it will support upto x4 ,x3 ,x2, x1
    for x4 max speed is 32Gbps
    for x2 max speed is 8Gbps,
    if it hasn't got anything written beside M2 then, it would mean general M2, that is maximum of 10gbps,
    actually x4 and its supreme bandwidth is borrowed from PCIe lanes, normal / fundamental M2 dont have that implementation, its the motherboard manufacturer that later taken bandwidth from PCIe lanes, and make it to 32Gbps,
    there is also one another example,
    USB 3.1 is designed to have 10Gbps speed, but some motherboard manufacturers ex : gigabyte in their gaming 3 and upwards motherboard, shared bandwidth from PCIe lanes, then made it (advertising it) 32Gbps USB 3.1.
    So your motherboard has the capability of running the fastest NVMe SSD of market also (samsung 960 pro M2),
  10. Hello peeps, I have the Gigabyte Z97 D3H mother and I'm planning to buy the Intel SSD 600p series 1tb to use as a data storage. I am wondering if it would be compatible with my motherboard. I read in a forum somewhere that the Z97 D3H has a m.2 in PCIE 2.0 x4 lane, but I'm not sure if it's true or not. If it's not compatible should I get this add on? Addonics ADM2PX4 M2 Pcie Ssd Pcie 3.0 4-lane Accs Adapter, I'm only using 1 GPU on the motherboard anyway. I don't mind spending an extra $20 to get an add on. Or Second option, get a Samsung 950 Pro 512GB instead. Thanks for the help.
    I found the forum that says the motherboard is PCIE 2.0 x4 here is the link.
  11. Z_Learner said:
    Hello peeps, I have the Gigabyte Z97 D3H mother and I'm planning to buy the Intel SSD 600p series 1tb to use as a data storage. I am wondering if it would be compatible with my motherboard. I read in a forum somewhere that the Z97 D3H has a m.2 in PCIE 2.0 x4 lane, but I'm not sure if it's true or not. If it's not compatible should I get this add on? Addonics ADM2PX4 M2 Pcie Ssd Pcie 3.0 4-lane Accs Adapter, I'm only using 1 GPU on the motherboard anyway. I don't mind spending an extra $20 to get an add on. Or Second option, get a Samsung 950 Pro 512GB instead. Thanks for the help.
    I found the forum that says the motherboard is PCIE 2.0 x4 here is the link.


    yes, if your m2 slot is 2.0 x4, then maximum bandwidth is 4*4 = 16Gbps,
    which will bottleneck 600p series.
    and if you have a x16 pci slot extra (which work minimum x4 mode) then just buy the adapter and add the m2 to adapter and intall the adapter into you pcie slot.nothing to worry
    and for your convenicence,
    you can buy toshiba OCZ RD400 , which is cheaper than other NVMe ssd and offer also great speed.
    choice is yours. Intel mainly offer better read speed only in the 600p series, writing speed is same as SATA3 hence the price is less.
  12. JohnnyLucky said:
    The vast majority of Z87, Z97, Z107, and X99 motherboards can support some type of M.2 solid state drive but there may be some restrictions. M.2 operation requires the use of several PCIe 3.0 channels or PCIe 2.0 channels to transmit and receive data. Graphic cards and sound cards also use PCIe channels.

    You already know that the Z97 motherboard has one M.2 port. The problem is there are several M.2 variations. Here are the current possibilities:

    M.2 3.0 x 4 - State of the art M.2 ssd that uses 4 PCIe 3.0 channels for proper operation. The M.2 port on the motherboard is sometimes referred to as an Ultra M.2 port. It is the appropriate port for the Samsung 950 Pro ssd.

    There are other M.2 ssd's that either use PCIe 2.0 or use fewer PCIe channels:

    M.2 2.0 x 4
    M.2 2.0 x 2
    M.2 SATA 3

    You will need to check your motherboard manual or the company web site to determine if the M.2 port can support an M.2 3.0 x 4 ssd like the 950 Pro. A lot of the Z87 and Z97 motherboards had M.2 ports for M.2 2.0 x 2 ssd's that would not fully support an M.2 3.0 x 4 ssd. With the exception of ASRock, the other motherboard manufacturers did not do a very good job of fully identifying the M.2 ports. You will have to find a little more information about the M.2 port on your motherboard. Hopefully the information is in the owners manual or the manufacturers web site.

    The addition of M.2 ports on the the motherboard required the use of addtional PCIe channels. Unfortunately Intel resisted adding chipset support for additional PCIe channels until recently. The lack of a sufficient number of PCIe channels resulted in some awkward solutions:

    Some motherboards reduced the number of channels available to graphic cards. The cards might be reduced from PCIe 3.0 x 16 down to PCIe 3.0 x 8. Graphic card performance is reduced by about 5%. That is not a terrible hit in performance.

    Some motherboards reduce the number of SATA 3 ports that are available. For example,the MSI Z107 Titanium motherboard has two M.2 3.0 x 4 ports. If I install a 950 Pro in each port, then all of the standard SATA ports are disabled except for two ports. The M.2 ports do not reduce the performance of graphic cards

    Some high end motherboards add an expensive PLX chip to handle M.2 ssd's. An example would be the ASRock Z97 Extreme9 motherboard. The PLX provides direct data transmission between the M.2 ssd's and the cpu. It is actually possible to run two graphic cards in SLI at PCIe 3.0 x 16 each and still be able to run two M.2 ssd's.

    The Samsung 950 Pro uses the new NVMe protocol instead of AHCI. A motherboard would have to have a UEFI BIOS, an Intel chipset, and a Microsoft Windows operating system that support the NVMe protocol. You would have to do the following:

    Check for any BIOS updates. Sometimes the updates include new and improved support for the NVMe protocol.

    Check for any Intel chipset upates. Sometimes the updates include new and improved support for the NVMe protocol.

    Windows 7, 8, and 10 can support the NVMe protocol. Again you will have to check for updates or fixes that can improve NVMe support. NVMe is new so things could get a little complicated.

    Finally Samsung has issued their own NVMe driver for the 950 Pro. Reviews and articles indicate the Samsung NVMe driver is better than the Windows NVme drivers.

    Some modern motherboards still provide a PCIe 2.0 slot. That does not mean you should purchase a PCIE 2.0 ssd or an M.2 ssd with an adapter card. M.2 3.0 x 4 ssds are backwards compatible.

    It might be confusing but for all practical purposes it is just a matter of checking requirements and specifications.




    this was such an incredibly useful post for me to read for my build. thankyou very much!!!!!
  13. shamsul_arefin said:
    Z_Learner said:
    Hello peeps, I have the Gigabyte Z97 D3H mother and I'm planning to buy the Intel SSD 600p series 1tb to use as a data storage. I am wondering if it would be compatible with my motherboard. I read in a forum somewhere that the Z97 D3H has a m.2 in PCIE 2.0 x4 lane, but I'm not sure if it's true or not. If it's not compatible should I get this add on? Addonics ADM2PX4 M2 Pcie Ssd Pcie 3.0 4-lane Accs Adapter, I'm only using 1 GPU on the motherboard anyway. I don't mind spending an extra $20 to get an add on. Or Second option, get a Samsung 950 Pro 512GB instead. Thanks for the help.
    I found the forum that says the motherboard is PCIE 2.0 x4 here is the link.


    yes, if your m2 slot is 2.0 x4, then maximum bandwidth is 4*4 = 16Gbps,
    which will bottleneck 600p series.
    and if you have a x16 pci slot extra (which work minimum x4 mode) then just buy the adapter and add the m2 to adapter and intall the adapter into you pcie slot.nothing to worry
    and for your convenicence,
    you can buy toshiba OCZ RD400 , which is cheaper than other NVMe ssd and offer also great speed.
    choice is yours. Intel mainly offer better read speed only in the 600p series, writing speed is same as SATA3 hence the price is less.


    Why would the intel 600p bottleneck? It means he will cap at the Max speed of pci-e 2.0x2/4? And if so what is the Max read/write speed I'll get?
    This drive is 1600/500
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