Performance issues on some tracks

Fernando Deutsch · Dec 6, 2017

Bought the European track pack and while testing SPA I got very worried, as I have very bad FSP on many parts of the track. I initially though it has to do with my hardware and start to tweak my settings, only to realize two hours later the real problem is the SPA track itself.

Besides SPA and the Moscow Raceway, the rest of the tracks has good FSP performance. Its a shame as SPA is probably an all favorite to everyone. Does anyone else has the same situation with these tracks?

Also, is there any config guide for graphic settings around?

Case_ · Dec 13, 2017

@RasmusP What you're describing doesn't sound like a setting issue, though... If you're getting 50 % GPU usage and 40 % CPU load with no single core being maxed out, that to me suggests there's some other issue at play.

BTW, MSI Afterburner can show you the usage for individual cores/threads, you just have to enable it in the OSD settings.

Anyway, my settings really are nothing special. I run at 1920x1200, fullscreen with vsync off (framerate limited to 60 via Afterburner), and I currently use these settings. Note that I was currently testing some stuff and trying to lower my CPU/GPU load for streaming, so I have some things set lower than I know I could:

Mirrors: On
Track level detail: Medium (can use high no problem)
Car LOD distance setting: Medium (can use high)
Particle detail: High
Tiremarks: On
Specular: On
Car reflection quality: Low (can use medium NP and often even high)
Track animations: On
Shadows: Medium (can go to high most of the time)
Car shadows: On
Contact shadows: 32
Shadow split: On
Multi-sampling: 4xAA
FXAA: Off
Bloom: On
Depth of field: On
Motion blur: Fast
Motion blur quality: Low
Light shafts: On
Lens effects: On
Track texture quality: High
Car texture quality: Medium (can use high NP)
Rear view mirror quality: Low (can go higher)
Shader quality: High
Visible cars: 25 (but setting it higher, even at full, doesn't make that much of a difference TBH)
Opponent cockpits: On

On top of that, I'm using 8QxMSAA and 2xSGSSAA via nVidia Inspector to get rid of the shadow flicker. I'm getting around 70-80 % GPU usage on average (single 970), which I'm fine with. I could likely go to 4xSGSSAA, but that means getting closer to 100 % GPU usage, which I don't want to do (want to have some overhead for streaming) and I can't really see much difference anyway, so why bother.

RasmusP · Dec 13, 2017

Martin Fiala said:
@RasmusP What you're describing doesn't sound like a setting issue, though... If you're getting 50 % GPU usage and 40 % CPU load with no single core being maxed out, that to me suggests there's some other issue at play.

BTW, MSI Afterburner can show you the usage for individual cores/threads, you just have to enable it in the OSD settings.

Anyway, my settings really are nothing special. I run at 1920x1200, fullscreen with vsync off (framerate limited to 60 via Afterburner), and I currently use these settings. Note that I was currently testing some stuff and trying to lower my CPU/GPU load for streaming, so I have some things set lower than I know I could:

Mirrors: On
Track level detail: Medium (can use high no problem)
Car LOD distance setting: Medium (can use high)
Particle detail: High
Tiremarks: On
Specular: On
Car reflection quality: Low (can use medium NP and often even high)
Track animations: On
Shadows: Medium (can go to high most of the time)
Car shadows: On
Contact shadows: 32
Shadow split: On
Multi-sampling: 4xAA
FXAA: Off
Bloom: On
Depth of field: On
Motion blur: Fast
Motion blur quality: Low
Light shafts: On
Lens effects: On
Track texture quality: High
Car texture quality: Medium (can use high NP)
Rear view mirror quality: Low (can go higher)
Shader quality: High
Visible cars: 25 (but setting it higher, even at full, doesn't make that much of a difference TBH)
Opponent cockpits: On

On top of that, I'm using 8QxMSAA and 2xSGSSAA via nVidia Inspector to get rid of the shadow flicker. I'm getting around 70-80 % GPU usage on average (single 970), which I'm fine with. I could likely go to 4xSGSSAA, but that means getting closer to 100 % GPU usage, which I don't want to do (want to have some overhead for streaming) and I can't really see much difference anyway, so why bother.

I had a long discussion with @Neilski about that subject and I honestly didn't understand it completely and can't find an easy explanation, but:
Imagine a Single Thread application like you need to put 1 nail into a wall.
There are applications where only one core ("one person") hammers on that nail.
But mostly the OS decides to use all 8 threads (persons) to hit the nail once and then do other stuff while waiting to be able to hit that nail again. But only one person can hit the nail at the same time.
So even if it's only one "main thread", Windows kind of shuffles it around. Even with Afterburner etc. you only see an average so it looks like no core is actually really used but when you dig deeper you'll find that the CPU is limiting.

You can easily test this by setting the resolution to 800x600 and deactivating Anti Aliasing. You'll then get the maximum fps the CPU can output. I tested this for a few games and had a look with process explorer. It adds up! The more threads, the higher the overall CPU usage and no thread can go above the "100%/threads" = 12.5% for my i7.

Raceroom is hitting these 12.5% with its main thread every time my fps drop below 60. When I deactivate the limiter/vsync, it's constantly hitting the 12.5%.

Anyway: I lowered the settings like you noted down and up to 30 cars are running fine now.
Thanks for that!

Reflections, shadows, car shadows are the settings that are giving me the highest boosts.

btw: yeah I use 2x SGSSAA too. Could use 4x but then I can't stand AC or rF2 after getting used to super smooth shadows

PS: same thing with the thread and CPU happens in AC if I enable too many apps. With limit at 60fps I can see how the one main thread goes higher and higher the more apps I enable. The moment it comes close to 12.5% my fps go down.