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    USB-C and external GPU potential?

    Discussion in 'e-GPU (External Graphics) Discussion' started by Goren, Mar 19, 2015.

  1. Goren

    Goren Notebook Virtuoso NBR Reviewer

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    USB C seems to be the big topic these days, and while I'm not too familiar with it, what is the potential with USB C being used for external graphics cards on notebooks?
     
    Goren, Mar 19, 2015
    #1
  2. octiceps

    octiceps Nimrod

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    Not enough bandwidth

    USB 3.1: 10 Gbps bi-directional
    PCIe 3.0 x16: 32 GBps ( 256 Gbps) bi-directional

    So full PCIe still has ~25x the bandwidth
     
    octiceps, Mar 19, 2015
    #2
  3. Craig9080

    Craig9080 Notebook Consultant

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    Yeah, it's unfortunate but nothing matched PCIe right now. Even the AW GA cuts down the lanes severely
     
    Craig9080, Mar 22, 2015
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  4. viilutaja

    viilutaja Notebook Consultant

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    It has more than enough bandwith for e-gpu.
    I have Lenovo X230 and I am running desktop GTX 460 through it's ExpressCard 2.0 slot! It has pci-e 2.0 x1 lane and bandwith 5 Gbps.
    Compared to my desktop motherboard pci-e 2.0 x16 slot, i tested the GTX 460 before, the GPU score in 3Dmark13 firestrike was only 10-15% slower than in x1 pci-e slot (5Gbps).
    So USB 3.1 has enough bandwith for e-gpu solution. Only problem maybe USB latency.
    If somebody could implement e-gpu solution to USB-type C (USB 3.1), which has power output to 100W and speed 10gbps- it would be awsome!
     
    viilutaja, Aug 19, 2015
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  5. viilutaja

    viilutaja Notebook Consultant

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    Look at this video. 6990 tested in 16x vs 8x vs 4x slot. I know that in the video he does not test HD6990 in 1x pci-e slot, but You can see from the video, that overall scores different very little from each other.
     
    viilutaja, Aug 19, 2015
    #5
  6. octiceps

    octiceps Nimrod

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    GTX 460?! Dude, that's ancient. Today's mainstream cards are easily 3x as fast.
     
    octiceps, Aug 19, 2015
    #6
  7. Mr.Koala

    Mr.Koala Notebook Virtuoso

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    Enough bandwidth or not, the latency is going to kill it.

    Even PCIe latency is considered a disadvantage for dGPUs. USB is a disaster compared to that.
     
    Mr.Koala, Aug 19, 2015
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  8. moviemarketing

    moviemarketing Milk Drinker

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    20Gbps TB2 connection seems to be fast enough to handle 780Ti @ about 85-90%.

    Hopefully the new 40Gbps TB3/USB 3.1 Type C ports can handle 980Ti and Pascal cards.
     
    moviemarketing, Aug 19, 2015
    #8