CS2 Input Lag Explained - The Monolithic 64 Hz Client Simulation Tick Stalls the Render Thread

[soul4kills]

These are moontrances readings.

rtss500.png (190.23 KiB) Viewed 315 times

I don't understand how someone with such smooth readings as this would still complain about poor input lag. These readings are perfect and smooth. Are you using gsync+vsync and reflex at ultra?

For myself If I leave my frames uncapped without gsync and vsync. Gaming feels horrible. gsync+vsync does wonders for game feel.

[Moontrance]

I don't understand how someone with such smooth readings as this would still complain about poor input lag.

Cuz smooth frame pacing is achieved thru buffering in this case. Imagine 10ms window, 1 frame takes 4ms, 4 another takes 1.5ms each. Frame limiter buffers those 5 frames and gives you one by one each 2ms. Congrats, you achieved perfect pacing at the cost of 10ms input latency or in another words you get effective input latency of non-buffered 100 FPS. That's fine for non-competitive titles, or at least not FPS genre, cuz aim feels way off.

[ArkoN]

I’ve got a 9800X3D and a 4080 Super. I play at 1280x960 with Reflex On and uncapped FPS.

At low settings, the game doesn’t feel as smooth, even though I’m getting high FPS. It feels like I’m too CPU-bound and the GPU isn’t being utilized enough. When I switch to the High preset, the GPU gets more load and the game feels noticeably smoother, with better frametimes.

Have you noticed the same thing, and what settings are you using for test??

That's basically the only thing you can do right now if you don't want to use external limiter or underclock GPU. I doubt you have better frametimes with more gpu load. That's the whole point of adding more GPU load, your best frametime will be lower and it will smooth out that spike during tick processing. I tried both low and high presets while doing tests and graph confirms what you're saying. It's interesting many pros actually use ridiculous settings that adds GPU load like 8x MSAA and very high shadows, probably they know this issue or just naturally felt it.

You actually get the best 1% lows with 8x MSAA. I measured this many times myself and also just did see it recently in a youtube video: https://youtu.be/7VP0uGLJl_s?t=395 (but pls ignore the other parts oft his video, this guy has no clue about proper settings, he did not set 8X MSAA while knowing that Donk (the best player in the game atm) has set 8X MSAA while showing that this even gives you the best 1% lows...

I tried todo a lot of CS2 Optimization for my System just to figure out, that the Game sucks My current setup is capping frames at 400fps atm, that feels the best. The best Benchmark results on the 1% low side you get with uncapped fps.

[soul4kills]

I’ve got a 9800X3D and a 4080 Super. I play at 1280x960 with Reflex On and uncapped FPS.

At low settings, the game doesn’t feel as smooth, even though I’m getting high FPS. It feels like I’m too CPU-bound and the GPU isn’t being utilized enough. When I switch to the High preset, the GPU gets more load and the game feels noticeably smoother, with better frametimes.

Have you noticed the same thing, and what settings are you using for test??

That's basically the only thing you can do right now if you don't want to use external limiter or underclock GPU. I doubt you have better frametimes with more gpu load. That's the whole point of adding more GPU load, your best frametime will be lower and it will smooth out that spike during tick processing. I tried both low and high presets while doing tests and graph confirms what you're saying. It's interesting many pros actually use ridiculous settings that adds GPU load like 8x MSAA and very high shadows, probably they know this issue or just naturally felt it.

You actually get the best 1% lows with 8x MSAA. I measured this many times myself and also just did see it recently in a youtube video: https://youtu.be/7VP0uGLJl_s?t=395 (but pls ignore the other parts oft his video, this guy has no clue about proper settings, he did not set 8X MSAA while knowing that Donk (the best player in the game atm) has set 8X MSAA while showing that this even gives you the best 1% lows...

I tried todo a lot of CS2 Optimization for my System just to figure out, that the Game sucks My current setup is capping frames at 400fps atm, that feels the best. The best Benchmark results on the 1% low side you get with uncapped fps.

By setting 8x MSAA they are shifting more load to the GPU to get it out of being CPU bound. It will drop your FPS but you reduce the frame queue backpressure/backlog, and this is where that input latency comes from or that muddy feeling. Do people not understand uncapped frames cause you to be CPU bound? Frametime stability is important too. It's what causes desync too, as other game threads like network and input finish before the main game thread.

I tested it myself and used capframex. I uncapped my frames game felt horrible, even though the readings were great with good frametimes and lower over all latency, which was way better than my capped settings. Compared to when i am capped with gsync+vsync+reflex@boost.

edit: my uncap load% avg, single threaded cpu=69 gpu=98 (game feels bad). my capped load% avg, single threaded cpu=58 gpu=69 (game feels great). i'm starting to believe most people complaining about input lag are just pushing their hardware too far causing overloaded situations or bounded situations. Try to be more conservative and leave some overhead for those spikes in scene complexity.