Is there a motherboard that supports Intel i9 (7900x for example) and PCIE 3.0 4x16?

I am looking for a motherboard that supports Intel i9 and PCIE 3.0 16x16x16x16. Memory needed is 64GB-128GB. 256GB would be even better. Is there such a motherboard?
Reply to modeonoff
19 answers Last reply
More about motherboard supports intel 7900x pcie 4x16
  1. No. The CPU does not have enough lanes, there is no intel CPU that I am aware of which has 64 pcie 3.0 lanes. The 7900x has 44.
    Reply to Dunlop0078
  2. None.

    The closest you can get is the Asus ROG Rampage VI Extreme where its four PCIe3.0 x16 slots can run in x16/x8/x8/x8 mode (using a 44-lane CPU such as the i9-7900X). Memory capacity supported is up to 128GB (max).
    Reply to raisonjohn
  3. Thanks. The Threadripper has 64 PCIe lanes. Why there is also no motherboard the supports x16/x16/x16/x16?
    Reply to modeonoff
  4. For TR4-socket motherboards, closest you can get is x16/x8/x16/x8. There are only 7 mobos available (as of my counting), and 5 of which support those modes. See here:

    The other PCIe lanes are distributed by motherboards on M.2 slots:

    So, for the 64x PCIe lanes: 48x goes to the PCIe3.0 x16 slots + 12x goes to the PCIe3.0 x4 M.2 slots + 4x goes to the media interface link between CPU and Chipset.

    If you are really looking for a motherboard that supports x16/x16/x16/x16 and 256GB RAM capacity, then, you should be looking at workstation mobos such as the Asus X99-E WS or the dual-CPU Asus Z10PE-D8 WS.

    Asus X99-E WS (

    8 x DIMM, Max. 128GB, DDR4 3200(O.C.)/3000(O.C.)/2800(O.C.)/2666(O.C.)/2400(O.C.)/2133 MHz Non-ECC, Un-buffered Memory
    8 x DIMM, Max. 128GB, DDR4 2400/2133/1866 MHz ECC, Un-buffered Memory
    8 x DIMM, Max. 256GB, DDR4 2400/2133/1866 MHz ECC, Register Memory

    Expansion Slots:
    40-Lane CPU - 7 x PCIe 3.0/2.0 x16 (single x16 or dual x16/x16 or triple x16/x16/x16 or quad x16/x16/x16/x16 or seven x16/x8/x8/x8/x8/x8/x8)
    28-Lane CPU - 7 x PCIe 3.0/2.0 x16 (single x16 or dual x16/x16 or triple x16/x16/x16 or quad x16/x16/x16/x16 or seven x16/x8/x8/x8/x8/x8/x8)


    Asus Z10PE-D8 WS (

    8 x DIMM, Max. 512GB, DDR4 1866*/2400/2133/1600/1333 MHz RDIMM, LR-DIMM Memory

    Expansion Slots:
    4 x PCIe 3.0/2.0 x16 (dual x16 or quad x8)
    2 x PCIe 3.0/2.0 x16 (dual x16)
    1 x PCIe 3.0/2.0 x16 (dual x8)
    Reply to raisonjohn
  5. Thanks for your info. I have checked the Asus X99-E WS before. The product site mentions that it supports i7/i7 X Series and up to 256GB RAM. From the Intel page, CPU likes the i7-7700K supports a max of 64GB only. Perhaps I am missing something. Could you please clarify?
    Reply to modeonoff
  6. The Asus X99-E WS is an older platform having an LGA 2011-v3 socket. The i7-7700K is a newer-gen CPU having an LGA 1151 pinout. They are not compatible (the CPU won't physically fit in the socket).

    Asus X99-E WS (

    Build in Intel® Socket 2011-v3 Core™ i7/Core™ i7 X-Series Processors
    Supports Intel® 22 nm CPU
    Intel® Socket 2011-v3 for Intel® Xeon® processor E5-1600 v3 product family
    Intel® Socket 2011-v3 for Intel® Xeon® processor E5-2600 v3 product family
    Intel® Socket 2011-v3 for Intel® Xeon® processor E5-1600 v4 product family
    Intel® Socket 2011-v3 for Intel® Xeon® processor E5-2600 v4 product family

    Intel i7-7700K (

    Lithography: 14 nm
    Sockets Supported: FCLGA1151
    Reply to raisonjohn
  7. Thanks for the clarification, raisonjohn. So, there is no new platform that support x16x16x16x16 and 128-256GB RAM? It looks like motherboards that support x16x16x16x16 are compatible with older, slower CPUs.

    I considered Threadripper but no motherboard supports x16x16x16x16. In addition, I read that there are some issues with PCIe. Perhaps it is better to stay away from it?

    I plan to use the computer for data science, deep learning, machine learning, Matlab and CAD. I plan to use 1-2 Nvidia 1080Ti GPU initially but may add to 4 GPU at the end.
    Reply to modeonoff
  8. You're welcome.

    Yes, as of this date, there are none. Though I do not have information if there are some being/going to be developed later on similar to the older platform motherboards that meets your requirements.

    Note that you won't see a significant/noticeable difference using video cards on a PCIe3.0 x16 speed (i.e, 15,760 MB/s) versus a PCIe3.0 x8 speed (i.e., 7,880MB/s), despite its 66.7% difference in bandwidth, as GPUs won't saturate all the bandwidth of such high-speed PCIe lanes.
    Reply to raisonjohn
    Question from modeonoff : "Why Intel and AMD don't make 2017 CPUs that support PCIe 3.0 16/16/16/16"

    modeonoff said:
    I have a hard time in finding a motherboard that supports PCIe 3.0 16/16/16/16 and CPU released in 2017. Those motherboards that support PCIe 3.0 16/16/16/16 are only for older and slower CPUs that run below 3.5GHz. How come?

    Gam3r01 said:
    Because there extremely little to no need for a motherboard with 4 full x16 lanes, and when most processors dont carry that many PCIe lanes either.

    modeonoff said:
    People who use CUDA and GPU computing need 4 full x16 lanes. Why they don't make processors that carry that many PCIe lanes? From motherboard websites, I can only find motehrboards that support that many lanes with CPUs few generations older running at about 2GHz.

    Gam3r01 said:
    Someone doing work like that can get by with x8 lanes no problem.
    A threadripper setup would probably be ideal, though it isnt 4x16. But it dosent need to be.

    If it used to be a thing, but hasnt been implemented for years, there is probably a good reason for it.
    (Hint: Nobody needs it).

    miner use x1 just fine.
    Reply to rgd1101
  10. If I am willing to settle with a system having three GPU running at full speed (i.e. PCIE 3.0 x16x16x16) and the fourth one at x8, about 128GB RAM (256Max would be the best), over 8 cores at 4GHz or above, what CPU-motherboard do you recommend? It seems that Threadripper motherboards can only support two PCIE 3.0 at x16.

    I know that there is no noticeable difference between x8 and x16 in gaming but for CUDA GPU computation, I heard that having GPUs running at x16 makes a big jump in performance.
    Reply to modeonoff
  11. Unfortunately, there's also no current motherboard that I know of having PCIe3.0 x16/x16/x16/x8 and with 128GB RAM. You are correct that TR4 mobos, as of this date, only has x16/x8/x16/x8 (and they are very limited models to choose from).

    Only available mobos that fits your triple or quadruple x16 speed requirements are the very selected EEB-form factor, LGA2011v3-socket X99-chipset or C1612-chipset mobos I mentioned above, that is, if you are willing to purchase such older parts.
    Reply to raisonjohn
  12. Thanks for your information. I don't want to buy older parts. How likely will motherboard manufacturers make more expandable models that could fit my requirement? Given the large 64 PCI lanes, I cannot understand why the TR4 cannot even accommodate x16x16x16. Can't they devote unused PCI lanes to give users more PCIE 3.0 x16 lanes for the GPU?

    In case of settling for x16x16 or x16x16x8 for the time being, which CPU do you recommend? I am thinking about the i9 7920X, 7999X, TR 1900X, 1920X and 1950X.
    Reply to modeonoff
  13. Can't really say for sure when (or even if) they would make a consumer motherboard model with such features. What I have come across before are server boards (AMD's EPYC: that will feature single- or dual-socket CPUs with 128x PCIe lanes. For example: Gigabyte MZ31-AR0 (

    In the case of the 64x PCIe lanes of TR, all of those lanes are actually used up in the current TR4 motherboards available to date:
    - 48x lanes for the four PCIe x16 GPU slots (x16/x8/x16/x8)
    - 12x lanes for the three PCIe x4 M.2 slots
    - 4x lanes for the required CPU-Chipset communication link
    TOTAL = 64x

    Due to this 64x limit, TR4 motherboards cannot do four x16 (since 4 x 16 PCIe lanes will already use up all 64 lanes, and will lack the required 4x lanes for the CPU-Chipset link). I doubt they will ever do a three x16 GPU + one x8 GPU + 4x CPU-Chipset link (total of 60x) and will only have a single PCIe x4 M.2 slot (for a total of 64x) PCIe lane distribution on their models.

    i9-7920X: 12C/24T | 2.9GHz | 44 Lanes | ~$1130
    i9-7900X: 10C/20T | 3.3GHz | 44 Lanes | ~$1000
    TR-1950X: 16C/32T | 3.4GHz | 64 Lanes | ~$1000
    TR-1920X: 12C/24T | 3.5GHz | 64 Lanes | ~$790
    TR-1900X: 8C/16T | 3.8GHz | 64 Lanes | ~$530

    Comparing the above CPU's, the TR-1950X at $1000 is a good deal over Intel's offering. The TR-1920X is also hard to pass at only $800, if 12C/24T is more than enough but still gives you the 64 lanes you would probably need.
    More info here:
    Reply to raisonjohn
  14. Thanks for the analysis. Am I right that if I just insert the TR-1900X to the motherboard, I get 3.8GHz. If I insert the TR-1920X to the motherboard, I get 3.5 GHZ,etc.? I think I have seen some posts mentioning that overclocking the TR reduce the speed of the memory. Does not seem to be ideal.

    In both i9 and TR systems, do the base and OC frequencies apply to all the cores? I think for some CPUs, not all cores get the same frequency.
    Reply to modeonoff
  15. The clock speeds I posted in my previous reply are just the base clock speeds of each CPUs, i.e., 1900X at 3.8GHz, 1920X at 3.5GHz, and 1950X at 3.4GHz. Those are the base frequencies at all cores.

    The boost clock speeds of all Threadripper CPUs (as of this date) is up to 4.0GHz. Those are boost frequencies at up to four cores only.

    All the aformentioned Threadripper CPUs also have full XFR (Extended Frequency Range) technology, which automatically allows an additional +200MHz (+0.2GHz) on the four cores' boost frequency to make the four-core 4.0GHz run at 4.2GHz, provided, sufficient cooling.

    As far as all-core boost is concerned, the 1920X can boost all its 12 cores to 3.7GHz only; while the 1950X can boost all its 16 cores to 3.6GHz only.

    To give you an idea, here's an example graph of the Ryzen 7 CPU (not Threadripper, as I can't find a graph of such) showing how the base, boost, and XFR frequency works. Note that Threadripper CPUs are essentially two Ryzen 5 or 7 CPUs, so, for purposes of the Ryzen CPU graph below (a Ryzen 7 1800X), it only shows two cores can boost and only 100MHz for XFR (compared to four cores and 200MHz for TR CPUs).

    More info on these here:

    For the Intel i9 CPUs, the base frequencies also pertains to all cores, i.e., i9-7900X at 3.3GHz, and i9-7920X at 2.9GHz. The boost clock speeds of both i9 CPUs is up to 4.3GHz but up to two cores only. Similarly, the i9 CPUs also have a TBMT (Turbo Boost Max Technology) 3.0, which automatically allows an addition +100MHz to +200Mhz boost frequency on its 2 best performing cores. The i9-7900X can do 4.5GHz (i.e., +0.2GHz above boost) while the i9-7920X can do 4.4GHz (i.e., 0.1GHz above boost).

    As far as all-core boost is concerned, the i9-7900X can boost all its 10 cores to 4.0GHz only; while the i9-7920X can boost all its 12 cores to 3.8GHz only.

    More info here:
    Reply to raisonjohn
  16. Thank you very much for the info. I just knew about the base and boost speeds. Didn't know about the rest until now. What about the all-core boost for the 1900x? Is it difficult to achieve XFR and all-core-boost on both i9 and Threadripper platforms. From the posts I have read, the i9 CPUs run much hotter than the TRs.
    Reply to modeonoff
  17. All-core boost of 1900X is 4.0GHz (all 8 cores), while only four cores will do XFR of 4.2GHz.

    I'd highly consider the TRs (1920X or 1950X) than the i9s or the 1900X.
    Reply to raisonjohn
  18. Thanks. Know any Threadripper motherboard that has a PLX chip to allow quad PCIe 3.0 x16x16x16x16?
    Reply to modeonoff
  19. I will tell you, that the X299 Chipset's max number of PCI-E is 24. So 44+24=68.
    Reply to kowal6880
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