[Official] DX9 vs DX11 performance difference

Discussion in 'Technical & Support' started by 4thworld, May 4, 2017.

  1. Ari Antero

    Ari Antero Registered

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    I don`t think it is your CPU. If you read this post from @stonec you find the answer why: https://forum.studio-397.com/index....eezing-jumpy-display.57025/page-3#post-907561
    :)
     
  2. hitm4k3r

    hitm4k3r Registered

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    Thanks for th headsup Ari, but I am afraid it really is a problem with DX11and it's CPU utilization in general on my end with the recent build. I tested the USF and Radical now and I get those CPU spikes aswell. It is really wierd as I have been playing the DX11 beta pretty much since the beginning and never had those issues, especialy not in multiplayer, wich is a big slideshow with the 650s right now. This is how the CPU graphs look for the 650s in DX9 and DX11. They aren't 100% matching the same situation, but I guess you get the picture. That's the first lap of an AI race at Silverstone: CPU_Graph_650s_DX9.PNG CPU_Graph_650s_DX11.PNG
     
  3. stonec

    stonec Member

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    @hitm4k3r Those spikes look like the CPU is throttling down, maybe due to overheating or excessiver overclock (it's best to disable dynamic clock speed adjustment unless you're very concerned about the electricity bill). Have a look at the clock frequency while you are gaming and check if it stays constant.
     
  4. hitm4k3r

    hitm4k3r Registered

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    I have noticed that the temps get a bit higher, but that might be even caused simply by the fact that we have quite hot weather atm or by how DX11 stresses the CPU itself. And in general I am not using any kind of overclocking or stuff like that. What I find strange is that I only have those spikes in DX11. Went back to DX9 yesterday to have a bit of fun with the Flat6 mod at Oulton Park and it is running smooth as silk with 20 cars on track and it doesn't skip a beat. The charts I posted above, are with 10 cars. What I might test though is, how it behaves without dynamic clocking, so thanks for that tip. At the end I just hope that they can find the issue (wich seems to have been introduced with one of the latest builds), so that I don't have to use such drastic methods and can use my PC as allways. I could run the ealrier DX11 builds without any issues with 20 cars and online worked perfect once they fixed the weather lags. So fingers crossed :)
     
  5. MarcG

    MarcG Registered

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    DX9:
    Frames, Time (ms), Min, Max, Avg
    7398, 60000, 95, 179, 123.300

    DX11:
    Frames, Time (ms), Min, Max, Avg
    6825, 60000, 90, 154, 113.750

    Had a spare 5mins before Work and decided to give this a go, slightly lower performance in DX11 but nothing substantial or worrying and it was perfectly acceptable to "race" with (used the AI control both times).
     
    Last edited: Aug 29, 2017
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  6. Juergen-BY

    Juergen-BY Registered

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    DX11: Frames: 11028 - Time: 120000ms - Avg: 91.900 - Min: 71 - Max: 115
    DX9: Frames: 11639 - Time: 120000ms - Avg: 96.992 - Min: 76 - Max: 120
    To compare the both versions a wee bit more serious (for me) PP effects were complete disabled for the DX11 version (EPostProcessingSettings=0).
     
  7. DaVeX

    DaVeX Registered

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    Have you tried to move ffb to a separate core?
    Ifnot, go to your controller.json and locate an entry called "Use Thread". If that is set to "false" then change it to "true". That way SIM will use a separate thread (that can run on a different CPU core) to send the FFB update commands to the driver of your wheel.
     
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  8. MarcG

    MarcG Registered

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    Had some more spare time and did two different tests, All settings Off/Low then All settings Full/Max

    DX9 - Off/Low:
    Frames 15792
    Time (ms) 60000
    Min - 238
    Max - 296
    Avg - 263.200

    DX11 - Off/Low:
    Frames - 14112
    Time (ms) - 60000
    Min - 184
    Max - 285
    Avg - 235.200

    Obviously on my system there is no visual difference between the two results, DX11 slightly lower performance but in no way noticeable in game.

    DX9 - Full/Max:
    Frames - 4478
    Time (ms) - 60000
    Min - 59
    Max - 95
    Avg - 74.633

    DX11 - Full/Max:
    Frames - 4393
    Time (ms) - 60000
    Min - 54
    Max - 100
    Avg - 73.217

    The numbers are much closer than I was expecting with barely anything between the two versions, I was expecting a bigger drop in DX11 so that's a nice surprise to see it remain almost identical to DX9.

    -=-=-

    N.B. I will add doing a simple FRAPS Benchmark is not a guarantee that one is better than the other as with each Run of the Benchmark different things can happen on track resulting in different FPS, whilst the FPS change might not be huge it could result in varied Benchmarks. (If I get time I'll do the Replay Test as per the thread on the main forum)

    N.B.2 Post Effects was set to NONE and EPostProcessingSettings=0 in the Config_DX11.ini file for both DX11 tests.
     
  9. MarcG

    MarcG Registered

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    Purely because I was curious, DX11 with Ultra PE:

    Frames - 3246
    Time (ms) - 60000
    Min - 47
    Max - 61
    Avg - 54.100
     
  10. Emery

    Emery Registered

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    @MarcG & @Juergen-BY -

    What resolution/card and which track/car/weather combo? Otherwise the numbers are kind of useless without their context.
     
  11. MarcG

    MarcG Registered

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    1920x1080 Specs in profile, Default weather, Mclaren at Silverstone International
     
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  12. Juergen-BY

    Juergen-BY Registered

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    It`s not about the absolut numbers, but the difference. Cant see anything useless....tbh
     
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  13. TravisRoe666

    TravisRoe666 Registered

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    havent been playing for months since the DX11 issues when released
    I'll give it another go now, is the general consensus now that the average performance is better in DX11? I have a nice i7 build with GTX1070 that was running awful in early DX11 builds but immediately perfect returning to DX9 build.
    I'll report back in 2 days, any thoughts shoot through to me in case i end up back on here troubleshooting! :) :)
     
  14. stonec

    stonec Member

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    There hasn't been an update since July, so nothing has changed recently in that regard. I reckon there was one update in June that improved performance somewhat. Performance in DX11 on newer hardware should be within 10% of DX9 in my experience (usually a tad bit slower). On older Nvidia cards DX9 is much faster. Performance problems that are remaining I think are more due to ancient gMotor engine stuff (like excessive usage of RAM, CPU and PCI-E bandwidth), which sometimes prevents GPU from being 100% utilized.
     
  15. patchedupdemon

    patchedupdemon Registered

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    What is your typical ram and vram usage when racing.
    My vram is roughly around 1.5gb,so I have 4.5gb left doing nothing.
    Is there a way to make rf2 use up more vram,or is that on the devs
     
  16. Lazza

    Lazza Registered

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    You don't just use vram, it doesn't contribute to processing performance or anything like that.
     

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