Physx

Discussion in 'General Discussion' started by Alex656, Oct 3, 2020.

  1. Alex656

    Alex656 Member

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    I never understood if train simulator really uses physx and how; perhaps to reproduce smoke effects? Can nVidia video cards really give you an edge over AMDs that don't implement physx?
     
  2. Pookeyhead

    Pookeyhead Well-Known Member

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    I can't imagine Phys-X on a GPU giving you much of an advantage in Train Simulator. Also, unless "Big Navi" turns out to be something special, no one will be buying an AMD GPU for a few years any way.
     
    Last edited: Oct 4, 2020
  3. Tomas9970

    Tomas9970 Well-Known Member

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    I think the game uses PhysX to calculate physics of the trains themselves. Most likely running on the CPU and not even remotely resource-intensive enough to matter novadays.
     
  4. Pookeyhead

    Pookeyhead Well-Known Member

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    Yeah just edited my post... I meant Phys-x on a GPU... can't see why you'd need that.
     
  5. Matthew Wilson

    Matthew Wilson Well-Known Member

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    PhysX is used and it is loaded on the CPU rather than GPU, despite the CPU already struggling enough but to accommodate those who like to make toast as well as play games and bought an AMD card :D
     
  6. Pookeyhead

    Pookeyhead Well-Known Member

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    You mean one core struggling, while the other [insert number of cores here] sit there doing nothing ;)
     
  7. Alex656

    Alex656 Member

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    I know that physx is usually used to reproduce effect things like cloth animation, particle effects, fluid animations, etc. I can't imagine how it could be useful for the physics of a vehicle, a train in particular.
    I used train simulator 20xx both on nVidia (which implement physx in hardware) and Amd (physx runs on the cpu) mid-high-end cards but I never noticed appreciable visuals or performances differences (maybe for smoke effects?); i assume that train simulator makes very modest use of physx or maybe doesn't use it at all.
    A clarification from DTG would be useful
     
    Last edited: Oct 5, 2020
  8. Peter Hayes

    Peter Hayes Well-Known Member

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    Alex656
    As I recall it was run on the cpu to accommodate simmers who used AMD graphics cards which at the time did not have that functionality.
    I don't know which is better the cpu or gpu version, but in the days of 32-bit TS20XX it made sense to use the cpu as the gpu could utilise a huge amount of VAS and that could affect "stability/performance".
     
  9. Matthew Wilson

    Matthew Wilson Well-Known Member

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    You never noticed a difference because the CPU is doing the PhysX work, there is no way to make an NVidia GPU perform PhysX for TS20XX, so whether you have AMD or NVidia is irrelevant for TS20XX where PhysX is concerned
     
  10. Alex656

    Alex656 Member

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    On the nVidia control panel I can choose whether to run physx on the cpu or on the geforce 2080 and this should automatically apply to all games using physx, including TS. The cpu is less efficient for running physx and the TS 3d engine runs on only one core; I still think that there are no big differences between nVidia and AMD cards simply because physx is not actually used by TS or makes minimal use of it.
     
  11. Peter Hayes

    Peter Hayes Well-Known Member

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    Alex
    I'm not sure how important this is wrt TS20XX
    From the PhysX website:
    Majority of PhysX SDK based games (TS20XX is one) are performing all physics calculations on CPU, running with decent performance regardless to GPU manufacturer.
    Adding a dedicated NVIDIA GPU and switching PhysX modes in drivers won't affect framerate or visual fidelity of such titles.


    http://physxinfo.com/wiki/Category:Games_without_hardware_acceleration and
    http://physxinfo.com/index.php?p=gam&f=cpu (TS is listed here)
     
  12. Pookeyhead

    Pookeyhead Well-Known Member

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    Is PhysX even still a thing?
     
  13. Alex656

    Alex656 Member

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    The links you posted are very interesting.

    We will probably never know what physx is really for in Train Simulator, I was just curious.

    Thanks everyone for the answers.
     
  14. Matthew Wilson

    Matthew Wilson Well-Known Member

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    Yes, you can select it on the NVidia settings, but if you enable the display of PhysX indication on there and then run TS you'll also notice that it is still running on the CPU, because that's what the software tells it to do.

    I have checked this stuff out, I don't just make unqualified statements.
     

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