M.2 "Key B" to PCI express adapter

Discussion in 'UDOO X86' started by ccs_hello, Apr 20, 2017.

  1. ccs_hello

    ccs_hello UDOOer

    Joined:
    Apr 15, 2017
    Messages:
    409
    Likes Received:
    155
    I saw few days back there was a question about this adapter
    (for example http://www.ebay.com/itm/PCI-E-4X-Fe...-Power-Cable-with-Converter-Card/172584561470 )

    I was looking for the same thing about a month ago and I actually order a board like that 30 days ago (different seller though.)
    I just received it today and would like to provide my initial investigation and some info...

    It is a NGFF M.2 socket 3 "Key M" (in PCIe flavor, not SATA flavor) to regular size PCIe x4 converter.
    Only 2 lanes of PCIe bus are brought out to the PCIe x4 socket and the side facing x4 and x8 of the socket is "open". I.e., you can plug in x1, x2 (never seen it), x4, x8, x16 PCIe cards except that max of 2 PCIe lanes can be used.
    It has a floppy disk type of molex power socket for optional 12V input (if your PCIe card is 12V powered.)
    The card's CFG1 is open so it is for PCIe flavor.
    Its CLKREQ# signal is brought out to a jumper pad (top side) and can use a zero-ohm resistor (or solder blob) to short to either Gnd or 3v3.
    None of the Prsnt#1 and other Prsnt#2 are linked (it doesn't matter since UDOO x86 does not use them either.) So bus lane width is determined in software config (EEPROM during PCIe initial negotiation.) (Its Prsnt#1 is tied to Gnd.)
    "M-"-key's pin 5,11 (PCI3-Tx- and PCI3-Rx-) are tied to Gnd. I think this is the way to inform the PCIe card not to use the 3rd and 4th lanes (Any one care to comment?) This is the same arrangement as in "B-key" as well as in UDOO x86 design. "B-key" type only has 2 PCIe lanes anyway.

    About the mod:
    I can cut the "B" key slot using a Dremel to fit the NGFF socket 2 2260 properly.

    I matched the pin used on UDOO x86 and the converted mapping. They matched very well.

    Also note:
    M.2's pin 54 (WAKE#) is connected to PCIe B11 (WAKE#.) In UDOO x86, this pin is not implemented.
    M.2's pin 50 (PLTRST#) is connected to PCIe A11 (Power Good.) Any one care to comment?

    In summary, I think I am very close to connect it and give it a try.
    To be continued...

    If you see a burning issue (pun intended), please let me ASAP.

    ccs_hello
     
    Gronis, MrGarapablo and GourouLubrik like this.
  2. mkopack

    mkopack Member

    Joined:
    Jun 14, 2013
    Messages:
    451
    Likes Received:
    21
    Ok, going to ask the obvious question.... WHY???

    If you needed PCI-E slots why didn't you just go with a ITX or similar board that has one?
     
    FirstGenGeek, Kilrah and fabio978 like this.
  3. ccs_hello

    ccs_hello UDOOer

    Joined:
    Apr 15, 2017
    Messages:
    409
    Likes Received:
    155
    Top side IMG_1080.JPG
     
    MrGarapablo likes this.
  4. ccs_hello

    ccs_hello UDOOer

    Joined:
    Apr 15, 2017
    Messages:
    409
    Likes Received:
    155
    Bottom side IMG_1081.JPG
     
    MrGarapablo likes this.
  5. ccs_hello

    ccs_hello UDOOer

    Joined:
    Apr 15, 2017
    Messages:
    409
    Likes Received:
    155
    Ultra small form factor :)
     
  6. mkopack

    mkopack Member

    Joined:
    Jun 14, 2013
    Messages:
    451
    Likes Received:
    21
    Sure, until you plug some damn card in that was meant for a full sized PC!

    Seriously, what the heck kind of card did you need to go this route???
     
  7. ccs_hello

    ccs_hello UDOOer

    Joined:
    Apr 15, 2017
    Messages:
    409
    Likes Received:
    155
    Probably DTV tuner, quad GigE card, or a better graphics card.
    BTW, it's fairly easy to get a regular PCIe x1 to PCIe x1 extender.

    ccs_hello
     
  8. ccs_hello

    ccs_hello UDOOer

    Joined:
    Apr 15, 2017
    Messages:
    409
    Likes Received:
    155
    Since a similar work is mentioned by Floris in this thread
    http://www.udoo.org/forum/threads/heres-looking-at-you-egpu.4246/

    I thought I might just well give mine a try.
    A quick summary, use PCIe x1 bus would work.
    I have yet to get 2-lane PCIe working. <-- this info is hard to find

    Note: this M.2 (2-lane) to PCIe adapter has a x4 PCIe slot.
    I used a .PCIe x1 to PCIe x1 extender to reduce the lane width from x2 to x1.

    In the future I might just trim the that M.2 to PCIe adapter's socket to just x1 size.
    IMG_1099.JPG
    ccs_hello
     
    MrGarapablo and estebanSannin like this.
  9. ccs_hello

    ccs_hello UDOOer

    Joined:
    Apr 15, 2017
    Messages:
    409
    Likes Received:
    155
    Direct-plug in a PCIe x1 Ethernet card
    IMG_1101.JPG
     
  10. ccs_hello

    ccs_hello UDOOer

    Joined:
    Apr 15, 2017
    Messages:
    409
    Likes Received:
    155
    The M.2 to PCIe adapter plugged into the UDOO x86 top M.2 slot.
    IMG_1100.JPG
     
    estebanSannin likes this.
  11. JCSelector

    JCSelector New Member

    Joined:
    Jun 23, 2017
    Messages:
    14
    Likes Received:
    0
  12. ccs_hello

    ccs_hello UDOOer

    Joined:
    Apr 15, 2017
    Messages:
    409
    Likes Received:
    155
    That M-Audio card is using PCI bus,
    while UDOO x86 is only offering PCI-express (PCIe) bus.

    PCI and PCIe are two different standards and cannot be used interchangeably.

    ccs_hello
     
  13. JCSelector

    JCSelector New Member

    Joined:
    Jun 23, 2017
    Messages:
    14
    Likes Received:
    0
    Thank you, it's a shame I can't use this audio card anymore. I think there is a pci to usb converter but I hear it won't work very well.
     
  14. LDighera

    LDighera UDOOer

    Joined:
    Jan 13, 2014
    Messages:
    197
    Likes Received:
    32
    Thanks for your very detailed and well expressed technical information on this somewhat arcane topic. I am grateful for your research.

    Because the Udoo X86 doesn't support the (latest and fastest) PCIe NVMe standard natively, is it possible to adapt the X86's 2260 PCIe M.2/NGFF slot to support a PCIe NVMe SSD card? If it's possible, will the X86's two-lane M.2 spec. affect throughput, and how might its performance compare to the PCIe SSDs? There's some information on NVMe here and here.

    I found this cache of adapters for sale on-line, and now I'm more confused than ever. :) There are only 86 adapters on that page. For the full boggle, peruse the complete 316 adapters offered on this page.

    The future: Intel Introduces Optane SSD DC P4800X With 3D XPoint Memory
    Intel’s first Optane SSD: 375GB that you can also use as RAM
     
  15. ccs_hello

    ccs_hello UDOOer

    Joined:
    Apr 15, 2017
    Messages:
    409
    Likes Received:
    155
    NVMe per standard, needs 4-lane PCIe bus. This is why M.2 standard body (NGFF org) modified their second gen socket standard (i.e., B-key socket, which can support up to 2-lane PCIe) which is used in UDOO x86's top M.2 slot, into a new 3rd gen standard.
    The 3rd gen standard has a slightly different signal assignment, now supports 4-lane PCIe, and is now the M-key socket.

    So in brief, if you go out buy a M.2 NVMe SSD, it will only come with the "M" key connector and it won't be seated in UDOO x86's top M.2 slot (which is B-key, the 2nd gen type) to avoid mistakes.

    ===============
    Regarding all type of adapters, they are all purposely built for specific reason. They are intended for people who understand the specs in depth (i.e., knowing what they are doing) to explore opportunities. They all have short-comings but may fit a specific purpose so long as the condition is met. And obviously the answer is NO, they are not universally adapting any format/any standard onto another.

    ccs_hello
     
    GourouLubrik and FirstGenGeek like this.
  16. ccs_hello

    ccs_hello UDOOer

    Joined:
    Apr 15, 2017
    Messages:
    409
    Likes Received:
    155
    Side note, (this has been discussed in the past)
    why UDOO x86 did not choose the 3rd gen M.2 standard instead?

    It is due to the CPU/SoC chosen. They are the entry level tier of Intel chip, the ATOM processor. Intel has to cheap out.
    Being in that tier, only 4 PCIe bus lanes are made available.
    In UDOO x86, lane 0 and 1 are used in the top M.2 slot, lane 2 is used by Realtek Ethernet controller, and the last lane, the lane #3 is used in M.2 lower slot ("E"-key M.2 slot, one of the first gen M.2 standards.)
     
    GourouLubrik likes this.
  17. ccs_hello

    ccs_hello UDOOer

    Joined:
    Apr 15, 2017
    Messages:
    409
    Likes Received:
    155
    re: post #13 Thank you, it's a shame I can't use this (PCI based M-Audio) audio card anymore...

    Sure, you can. Just need to think outside the box and go back to the past-time.

    Get a refurb SFF (small form factor) PC.
    The one I looked at recently costs $150-$160 shipped, has gen 3 Ivy Bridge Intel i5 quad-core CPU, 8GB RAM, 500 GB HD, Win 7 Pro license key.
    It has 2 PCI slots and one PCIe x1 slot and one PCIe x16 slot.
    Much more powerful performance-wise, just (much) bigger and consumes more energy.

    ccs_hello
     
  18. Chow Ming Cheeng

    Chow Ming Cheeng New Member

    Joined:
    Sep 17, 2018
    Messages:
    4
    Likes Received:
    0
    Hi,
    It has been some times now is it only pcie x1 lane can work but not pcie x2 lanes?
     
  19. Chow Ming Cheeng

    Chow Ming Cheeng New Member

    Joined:
    Sep 17, 2018
    Messages:
    4
    Likes Received:
    0
  20. ccs_hello

    ccs_hello UDOOer

    Joined:
    Apr 15, 2017
    Messages:
    409
    Likes Received:
    155
    Yes, UDOO x86's key-B slot is PCIe x2. You can see my post & pictures on using it with a SATA card with 2-lane PCIe.
     

Share This Page