Optimized Graphics Settings

To-Do

• Explain graphics settings in terms of system resources consumed and impact experienced by the user
• Provide a Problem & Solution Q&A that quickly identifies the graphics settings most likely to be related to a problem

Resources

• Optimal Graphic Settings for Automobilista 2

Terms

System Terms

• Sram/Smem (System Ram/System Memory)
  • Current system memory consumed
  • Exceeding available system memory will lead to memory swapping in and out from much slower cache/memory/disk resulting in choppy performance

GPU Terms

• Vram/Vmem (Video Ram/Video Memory)
  • Current video memory consumed
  • Exceeding available video memory will lead to much higher video memory swapping in and out from slower cache/memory/disk resulting in choppy performance

Image Terms

• Framerate (FPS)
  • Frames Per Second ie. how many images are being rendered per second
• Frametime
  • Time to render each frame (usually in milliseconds)
  • Smoother frametimes (less variability) improves visual fluidity
  • Rougher frametimes (more variability) causes choppier fluidity
• Jitter
  • Inconsistent frametimes
  • May not be noticeable if frametimes durations and variability are low enough
  • However, even low frametime with high relative variability can harm the user experience ex. target 8ms frametimes with sporadic 20ms+ spikes will feel like a poor experience
• Judder
  • Choppy visual fluidity due to jitter ie. inconsistent frametimes
  • Can also be due to framerate vs display refresh rate mismatch
• Stutter
  • More severe form of judder, visually noticeable
  • May be irregular ie. happen only every few seconds, when doing specific actions, or in specific areas
• Hitching
  • Momentary freeze or lag
  • Hitching is longer and more severe than stutter
• Freezing
  • Significant freeze or lag
  • Freezing is longer and more severe than hitching
• Ghosting
  • Pixels staying lit even after they should have been dark, due to pixel response times eg. an object moving left to right leaves ghosting behind it
• Persistence Blur
  • An optical illusion that can visually 'persist' an image due to how it's presented
  • TestUFO.com Persistence Demo - This animation creates a persistence-of-vision effect by panning an image behind tiny slits, like walking along a picket fence and staring through, or scanning through through the crack of a door.
• Overshoot (Overclocking pixels)
  • Pixel colour transition 'overshoots' its target colour and 'bounces' back to its correct colour, creating visual artifacting

Graphics Settings Impact

• Display
  • Resolution
    • GPU, Vram, Framerate, frametime, jitter, judder
  • Refresh Rate (Monitor)
    • Judder, Onscreen visual fluidity
  • Framerate
    • GPU, CPU, frametimes
  • Vsync
    • Onscreen visual fluidity
  • Gsync/FreeSync
    • Onscreen visual fluidity
  • Window Mode
    • User experience interacting with Windows ie. alt-tab, possible mouse focus issues in Windowed vs Borderless Window vs Fullscreen modes
• Graphics
  • Anti-Aliasing
    • GPU, Framerate, frametime
  • Post Processing
    • GPU, Framerate, frametime
  • Textures
    • GPU, Vram, Frametime, judder
  • Reflections
    • GPU, Framerate
  • Motion Blur
    • GPU, Framerate
  • Detail / Level of Detail
    • GPU, Vram, Framerate, frametime, judder
  • Shadows
    • GPU, Framerate, frametime, judder
  • Particles
    • GPU, Framerate, frametime, judder
• Rendering
  • Render Frames Ahead
    • GPU, CPU, Lag
• Visual
  • Filters
    • GPU, Framerate
  • Light Flares
    • GPU, Framerate
  • Bloom
    • GPU, Framerate
  • Heat Haze
    • GPU, Framerate, frametime, judder
  • Exposure Compensation
    • GPU, Framerate
  • Vignette
    • GPU, Framerate
  • Crepuscular Rays
    • GPU, Framerate
• Sim Racing
  • Track Reflection Detail
    • GPU, Vram, Framerate, frametimer, judder
  • Vehicle Reflection Detail
    • GPU, Vram, Framerate, frametimer, judder
  • Pit Crew Detail
    • GPU, Vram, Framerate, frametimer, judder
  • Rain Drops
    • GPU, Framerate, frametimer, judder
  • Screen Dirt
    • GPU, Vram, Framerate
  • Cockpit Mirrors
    • GPU, Vram, Framerate, frametimer, judder
  • Mirrors
    • GPU, Vram, Framerate, frametimer, judder

Graphics Performance Engineer

Fixes for poor performance symptoms presented in a problem and solution format:

...work in progress...

• Low framerate
• Inconsistent frametimes
• Judder
  • Stutter
  • Hitching
  • Freezing

Explainers

Frametime Jitter With High FPS Feeling Worse Than Sub-60 FPS

Good point. Sometimes it has to do with frametime jitter, too, not even raw FPS.

For example, I can push 120fps on most car/track mods but if it has enough frametime jitter, it can honestly at times feel worse than sub-60fps even though fps is reporting 120fps.

-Shovas

--

[quote="Scorpyo"]
Can you give more info about this, I may have that problem as your description describes it perfectly.
[/quote]

Jitter is when the time between frames is inconsistent. A perfect 60fps would have 16.6ms spaced frames. FPS is a per-second average and not all of those 60 frames are delivered with consistent time between each frame. So, you're watching 60 frames for 1 second and your eye can notice visual micro-stuttering, if inconsistent frametimes are present.

I'm not sure what level of jitter is too much but I'd probably say +/- 50% feels bad. Might be lower, not sure. For example, if 60fps delivered with consistent 16.6ms timing, that would be perfect, but if there were enough frames that took 8ms or 24ms, it would start to look bad in motion.

For GTR2, I suspect jitter is caused mostly by a lot of objects, or a moderate amount of objects with high polygon complexity, and in other cases maybe too many dynamic shadows.

I experience jitter in GTR2 with very high quality cars and tracks, usually converted from more complex sims.

It doesn't even have to be when your GPU or CPU are overloaded. Poorly optimized graphics pipelines in the game's engine ie. isiMotor can cause it when trying to push too much through them. I feel like this is the issue with GTR2 and complex objects/geometry and shadows.

If you have MSI Afterburner with RivaTuner Statistics Server (RTSS), you can add and customize an overlay to display frametimes and a frametime graph. It makes confirming what you're seeing a lot easier.

I tried my best to wrap my head around the various visual issues here:

https://www.simwiki.net/wiki/Optimized_Graphics_Settings

May also be helpful: Optimizing Monitors for Sim Racing

https://www.simwiki.net/wiki/Optimizing_Monitors_for_Sim_Racing

-Shovas