Z370/B360, PCIe Lanes, and slots

Discussion in 'Motherboards' started by balnazzar, Jul 11, 2018.

  1. balnazzar

    balnazzar [H]Lite

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    Mar 13, 2013
    Hi mates,

    Please help me with two questions I wasn't able to answer after *a lot* of googling.

    1. The vast majority of h370 and b360 boards with two mechanical 16X slots do have the following layout: the upper slot has 16 gen3 lanes by the CPU. The lower one has 4 gen4 lanes by the PCH.
    Now, I need to install two video card.One in the 4X slot for driving the monitor and gaming, and one in the 16X for computational purposes. The two cards won't be connected by a sli bridge, obviously.
    My question: is it doable? Will the 4X (PCH) slot provide video output?

    2. The z370 and the b360 seem to provide identical features: which are the differences??

    Thanks!
     
    Last edited: Jul 11, 2018
  2. acquacow

    acquacow Limp Gawd

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    You could use a pci-e gen1 4x and you'd only lose about 5 fps vs a gen3 16x slot. You don't need a ton of pci-e bandwidth in order to do gaming workloads on a GPU.

    For that same matter, you probably won't need that much throughput for your "computational" workload either.
     
  3. balnazzar

    balnazzar [H]Lite

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    I think I need full 16X for doing deep learning, it's very bandwidth intensive. There will be a lot of communication between RAM and VRAM, and that should occur at the best speed. Benchmarks show an average loss of 10/12% in terms of performance on an 8X gen3 slot, and over 50% on a 4X slot.

    However, the main issue is about the fact that the 4X slot is NOT driven by the CPU directly, but by the PCH. I hope I'll get the video output nonetheless..
     
    Last edited: Jul 13, 2018
  4. Denpepe

    Denpepe Gawd

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    Why not buy an SLI/x-fire capable one with x8-x8 split?
     
  5. balnazzar

    balnazzar [H]Lite

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    I need one card to go at full 16X gen3.

    On the other hand, I do NOT need any SLI/XF stuff. Two different cards doing different stuff.