How to test for PCI-Express bottleneck?

Discussion in 'Video Cards' started by TheForumTroll, Jan 9, 2020.

  1. TheForumTroll

    TheForumTroll [H]Lite

    Messages:
    68
    Joined:
    Oct 11, 2009
    Hello experts :)

    I'm running a brand spanking new GPU on a very dusty motherboard. Is it possible somehow to see the PCI-Express bus utilization and if it is bottlenecking the GPU? I know you can google some tests, opinions and theoretical numbers but I'd like to be able to see/test it myself if possible.
     
  2. Armenius

    Armenius I Drive Myself to the [H]ospital

    Messages:
    20,005
    Joined:
    Jan 28, 2014
    Motherboard and video card?
     
  3. DogsofJune

    DogsofJune 2[H]4U

    Messages:
    3,334
    Joined:
    Nov 7, 2008
    3dmark PCI Express feature test?
     
  4. crazycrave

    crazycrave Gawd

    Messages:
    618
    Joined:
    Mar 31, 2016
    gpu -z will test the PCI Express output the card is getting as in 1.0/2.0/3.0/4.0 as to kick start the 3D engine of the video card .

     
    Last edited: Jan 9, 2020
  5. TheForumTroll

    TheForumTroll [H]Lite

    Messages:
    68
    Joined:
    Oct 11, 2009
    It only shows which PCI Express the card is using though, right? No way to see how much it is using of the available bandwidth.

    Sorry, I'm not buying 3D mark pro just for this.
     
  6. Armenius

    Armenius I Drive Myself to the [H]ospital

    Messages:
    20,005
    Joined:
    Jan 28, 2014
    No, it shows how many lanes and what protocol are being used when the 3D engine is put under stress.

    You don't need the Pro version to get the 3D Mark PCI-E Feature Test, just the Advanced version. I bought it on Steam for $10 during a sale one year.

    You still haven't answered the question of what video card and motherboard. We can provide more answers if you provide this information.
     
  7. TheForumTroll

    TheForumTroll [H]Lite

    Messages:
    68
    Joined:
    Oct 11, 2009
    Oh, sorry I misread the comparison of 3dmark versions then. I'll go have another look.

    I haven't provided any hardware info because I wanted to be able to test it myself since it is for more than testing one PC. I was only looking to learn :happy:
     
  8. DogsofJune

    DogsofJune 2[H]4U

    Messages:
    3,334
    Joined:
    Nov 7, 2008
    Yeah, I wouldn't have suggested something you have to pay for unless it's exceptional and specific.
     
    Armenius likes this.
  9. crazycrave

    crazycrave Gawd

    Messages:
    618
    Joined:
    Mar 31, 2016
    Fire Strike will tell what the gpu is doing as if it below standard as they have a base line the cards should score as where your at .
     
  10. Mode13

    Mode13 Gawd

    Messages:
    728
    Joined:
    Jun 11, 2018
    The only thing you can do in this case is run a free benchmark and compare your GPU score to the results of the same card in another machine at the same GPU / Mem frequencies. Even firestrike will vary until you find a card running at the exact freqs (and only look at graphics score)

    Now, an RTX 2080Ti barely saturates PCI-E 3.0 x8, which is theoretically a little bit slower than PCI-E 2.0 x16

    I'm assuming you're using the P67 board in your sig, so I'm willing to bet if you have any bottleneck it would be negligible unless you're running a top end GPU OR SLI (SLI would be seriously bottle-necked on a modern high end card). Realistically the CPU and memory is always going to be the bottleneck in this situation long before you max out PCI-E 2.0 x16 IMO.

     
    Armenius likes this.
  11. Furious_Styles

    Furious_Styles [H]ard|Gawd

    Messages:
    1,521
    Joined:
    Jan 16, 2013
    Woah, shortcut OVERLOAD.
     
  12. Armenius

    Armenius I Drive Myself to the [H]ospital

    Messages:
    20,005
    Joined:
    Jan 28, 2014
    I'm a desktop shortcut kind of guy. Always have been since Windows 3.1. My home desktop is at least twice as full as that with shortcuts.
     
  13. defaultluser

    defaultluser [H]ardForum Junkie

    Messages:
    12,853
    Joined:
    Jan 14, 2006
    Yeah, unless you have a system you can compare to without a bottleneck (both CPU and connection speed), you're going to have to compare to someone online.

    Or you can just check the myriad tests already done on major websites, and compare you system's PCIe connection speed to that.

    RX 5700 XT PCIe 4.0 test (the 1080p tests are what matter):

    https://www.techpowerup.com/review/pci-express-4-0-performance-scaling-radeon-rx-5700-xt/23.html

    I wouldn't worry about bandwidth as long as you are still running PCIe 2.0 at x16. I doubt any system recent enough to power a modern graphics card will have anything less than 2.0. a 2% difference between 2.0 and 4.0 is lost in the noise!

    The RTX 2080 Ti is SLIGHTLY limited by PCIe 2.0 x16 (but it's still under 5%). As long as you have x16 PCIe 3.0, you're good for the next five years (and with PCIe 4.0, good for ten)!

    The tests require low resolution, because the geometry data from so many frames adds way more bandwidth. You should also make sure your CPU can keep up at those lower resolutions.
     
    Last edited: Jan 16, 2020 at 2:42 PM
  14. Shikami

    Shikami Gawd

    Messages:
    669
    Joined:
    Apr 5, 2010
    GPUz shows PCIe bus utilization via sensor tab.

    This is a fresh, just now, bench of Division 2. The bus interface high was 3%. I have seen it higher before but never much above ~8%-10% with a game, IIRC. Loads for other tasks such as computation are higher. Anyways, Bus Interface Load, lower portion of the window.

     
    Last edited: Jan 17, 2020 at 10:01 AM
    Armenius likes this.