Superliminal stuttering issues

So there is this game called “Superliminal”, it is nothing special but it has one weird issue I cant figure out.
It runs at stable 60 fps, my frametime (RTSS) is flatter than anime girl yet I’m getting the weirdest CONSISTENT stutter. It isnt random, it isnt in some special places, it ALWAYS there. Does not matter if i run borderless or exclusive, vsync or framelimiter. Game is built on Unity (2019) and uses DX11. As a baseline, I’m comparing it to Manifold Garden, using Unity 2019 as well and running butter-smooth.

So, my question is - can I use SpecialK to try to investigate the issue in some way and where do I start with SK?
(I understand many things can cause stutter but I want to at least eliminate something).

Turn on flip model in the D3D11 Swapchain settings, and the problem’s basically solved :slight_smile:

RTSS cannot do that and I don’t have much faith in its ability to actually graph frametimes accurately, it cannot even draw lines at an angle, which is important.

It is beyond me why Unity even allows new games to ship without enabling flip model by default, but they do :-\

Turn on flip model

But as I mentioned:

Does not matter if i run borderless or exclusive

shouldnt the flip model work if I force proper exclusive on Windows 7?

Flip model doesn’t work at all on Windows 7. You can get fullscreen exclusive, but that still comes with a lot of penalties that are configurable away in Windows 8.1 and newer.

Okay, so I cant even use SpecialK flipmodel for swapchain on Win7.

Then back to my original question - what metrics of SK I should look for starters?

No idea, unfortunately. I’m frankly surprised that Special K even works in Windows 7. I don’t remember all of its performance problems aside from the obvious lack of support for flip model.

My bad, I never said it works, I was just starting and was looking for options first, to get an “angle of attack”.
Thanks for the responses, I figured it is probably compiled against new API model in 8.1+ so it wont work. One of the reasons I use RTSS mainly.

Turn on flip model in the D3D11 Swapchain settings

Can SK actually show what flip model game uses by efault? Either directly or heuristically?

And which one would SK enforce in the case of your recommendation? There are multiple available for flip

Yes — it’s a part of the tooltip that gets shown when you hover over the frame buffer resolution (where it says BitBlt in exclusive fullscreen mode).

And SK enforces Discard on platforms that supports it (Win10).

Interesting. What will be used for 8.1+ and 8.0 respectively?

Those platforms don’t support Discard (Flip) so Special K makes use of Sequential (Flip) instead automatically. SK don’t actually provide an option between them – if the OS supports DXGI_SWAP_EFFECT_FLIP_DISCARD then that is what gets used, but if not then DXGI_SWAP_EFFECT_FLIP_SEQUENTIAL is used as a fallback.

Here’s the relevant section of code:

@Civ01 Btw, if you’re talking about the various flip scenarios possible that Jesse Natalie covers in the presentation modes of Windows 10, then it depends entirely on other factors beyond the actual swap effect itself (DXGI_SWAP_EFFECT_FLIP_DISCARD).

Those various scenarios basically kicks in automatically based on things such as resolution for the game window and whatnot. You can get some more information about those various scenarios in the below blog post:

Beyond those scenarios, Special K also exposes optional settings such as enabling waitable object for the swapchain, allowing screen tearing, and whatnot – basically allowing the user to configure the swapchain how they desire to attempt to squeeze out as much latency improvements as possible.

Edit: … And on that note, I guess most of these improvements are only available on Windows 10…


Yes, I’ve read that blog, but that information a bit too sparse. This gives me more insight:

Looks like the main effective difference between 2 FLIP models on Win10 FC and 8.1 is how compositor behaves if application is not the only thing that draws on the visible screen space. In case of Win10 in some cases it can eliminate latency by drawing straight into the backbuffer for overlay.

I wish someone would do proper testing/analysis between different models with some good HW and hight-speed camera.

Kaldaien is waiting for Nvidia to ship their new system latency toolkit to him, I believe, at which point he’s sure to start going even more crazy about lowering input latency wherever possible :laughing:

As long as he samples stuff properly, GamerNexus mentioned that the tool so powerful and simple to use it is very easy to produce incorrect data nad didnt even notice it and be 100% confident in results :stuck_out_tongue:

I don’t think you have to worry about that :stuck_out_tongue: I am as fastidious about collecting, interpreting and tuning performance data as any YouTube review site. I see performance statistics in my sleep :slight_smile:

I also have experience actually developing engines, so I know the various ways that input can be sampled.

Any ETA on delivery?

None whatsoever :-\ Their GPU manufacturing is not the only thing backed up and unable to meet demand.

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Unfortunate, hopefully the next batch will be not to far away and they can start sending these out again but I would have no idea how much of a back order there is for these units there’s probably at least some.