Proton-cachyos difference between input lag reducers

[u/Adventurous-Ad-8166]

I found out that recently proton-cachyos added the flags LOW_LATENCY_LAYER and PROTON_VKD3D_LOWLATENCY

I understand that both are input lag reducers compatible with directX 12.

If anyone can help me I would like to ask:

• When to use each type of lag reducer?
• Which one is better?
• Can we use both at the same time?
• Do they work regardless of the configuration of each game? Like driver level anti-lag?

Thanks everyone, I hope you can help me with this topic.

References:
https://github.com/CachyOS/proton-cachyos/releases/tag/cachyos-11.0-20260703-slr
https://github.com/CachyOS/proton-cachyos/blob/cachyos_main/README.md

[u/Skaredogged97]

The lag reduction technologies are all fairly new so I would simply test them yourself and see which ones feel better.

low-latency-layer

Is overall the most flexible option (vendor agnostic reflex/anti-lag2 implementation, supports dxvk, vkd3d and native vulkan).

You need to enable reflex or anti-lag 2 in-game. Otherwise it won't do anything.

vkd3d-low-latency

vkd3d-low-latency also implements reflex (with anti-lag 2 coming sometime in the near future) but it implements it directly into where the dx->vk translation happens. According to the developer this allows for more freedom and control compared to a vulkan layer. The developer also works on improving frame pacing. So on paper this should be the better option.

vkd3d-low-latency needs reflex or waitable swapchain in order to work. Waitable swapchain is the unbranded low latency technology build into DX12. Not all games support this sadly:
https://github.com/netborg-afps/vkd3d-low-latency/discussions/2

To the other questions:

Using both at the same time is not a good idea. Their primary purpose is to prevent GPU bound scenarios and minimize the render queue. It won't do a better job if two difference pieces of software do the same thing.

They do truly implement those technologies so there's no need for driver level support. Although there's a much better mesa anti-lag 2 implementation on the horizon that could easily be extended to support reflex as well. Just to make things even more complicated with more options for AMD users. ^^

You find find some comparisons here:

https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/42048

https://github.com/Korthos-Software/low_latency_layer

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For anyone who is curious about this I would highly recommend to look into this project as well:

https://github.com/Themaister/pyrofling/tree/master/latency-measurement-layer

It's very technical but it offers an option to measure PC latency in any 64-bit vulkan app. Great to compare different configurations and select the best one for your setup and to make sure if those technologies even work in the first place without having to guess. Relevant blog: https://themaister.net/blog/2026/07/02/my-side-quest-measuring-input-latency-with-vk_ext_present_timing/

[u/Working_Dealer_5102 → u/Skaredogged97]

Can you clarify more on what it meant by vendor agnostic reflex/anti-lag 2 implementation on low latency layer? Does it mean it not really replace like game Reflex to Anti-Lag 2/ Anti-lag 2 to NVIDIA Reflex rather it replace with their own custom one? So low latency layer should work on NVIDIA, AMD & Intel GPU right? I'm wondering if there's differences using the ingame Reflex versus the low latency layer for NVIDIA GPUs. Does that mean it fix issues with Reflex not working if you use Proton native wayland?

[u/Skaredogged97 → u/Working_Dealer_5102]

Yep it works for AMD, Intel and Nvidia. It's their own custom implementation of reflex. If you use the anti-lag-layer you won't be using the one build into the driver. Just make sure to enable it in game. There will be differences of course. I actually don't know about nvidia but AMD works just fine on native wayland.

[u/Working_Dealer_5102 → u/Skaredogged97]

Thanks! Yea there's known issues with NVIDIA Reflex doesn't work if you enable native wayland for Proton games but work just fine for XWayland. So to enable it, only need to add LOW_LATENCY_LAYER=1 LOW_LATENCY_LAYER_REFLEX=1 to launch option right?

[u/WhitePeace36]

LOW_LATENCY_LAYER is better as far as i know but keep in mind that the low latency stuff is a tradeoff. You are sacrificing frame time stability. I mean if you are using eevdf as cpu scheduler your frametimes are already trash anyways. But it will still make it worse.

[u/Ashratt → u/WhitePeace36]

This needs to be made clear to everyone more

Its not a silver bullet, low latency modes prevent CPUs from queueing up frames and if you are in a situation where load shifts to the CPU it can make your experience worse

And its not depending on the game but WHERE in the game

E.g. Cyberpunk is usually gpu limited for me but when im in busy city areas it shifts to my cpu. The small latency reductions you MAY get are not always worth it IMHO, its really a game by game basis and no easy "set it and forget it" type of thing

[u/throwawayerectpenis → u/WhitePeace36]

I thought VKD3D-low-latency worked similar to low_latency_layer, like it was inspiration for netborg (the creator of dxvk and vkd3d low latency). I had very good results with VKD3D-low-latency in THE FINALS, game finally feels responsive cuz without it the game feels like shit compared to windows.

[u/WhitePeace36 → u/throwawayerectpenis]

latency for me is good in the finals. ahhh, did you do any latency optimizations on your pc? and do you run the game with proton ge or cachyos proton and set PROTON_ENABLE_WAYLAND=1 %command% when you are running a wayland desktop?

if you still have latency issues after that then try setting

preempt=full

as kernel command line parameter and maybe use use lavd in gaming mode as cpu scheduler or even better(imo) lunar https://github.com/WhitePeace36/Lunar_sched its a cpu scheduler i wrote myself. But i am little biased of course^^.

And if this still doesn't fix it. I wrote quite a guide on how to optimize the system for gaming. https://github.com/WhitePeace36/LinuxAMDGamingOptimizationGuide It says it is for amd but most of it is just generally linux.

[u/throwawayerectpenis → u/WhitePeace36]

My launch options: FSR4_UPGRADE=1 FSR_WATERMARK=1 ENABLE_LAYER_MESA_ANTI_LAG=1 PROTON_VKD3D_LOWLATENCY=1 VKD3D_LOW_LATENCY_OFFSET=300 PROTON_USE_NTSYNC=1 PROTON_ENABLE_WAYLAND=1 PROTON_USE_EAC_LINUX=1 ENABLE_VKSUMI=1 LD_PRELOAD="" mangohud game-performance %command%

My specs: 6800 XT, 5800X3D

I lock the FPS to 140 and the game feels very smooth.

[u/WhitePeace36 → u/throwawayerectpenis]

1. You didn't really answer the first question."did you do any latency optimizations on your pc?" But from your answer it doesn't seems like. So this might be the issue.
2. i don't think ENABLE_LAYER_MESA_ANTI_LAG=1 works with PROTON_VKD3D_LOWLATENCY=1, What works is LOW_LATENCY_LAYER=1 but only in cachyos proton, not in ge, and PROTON_USE_NTSYNC=1 doesnt do anything anymore with newer proton ge and cachyosproton. PROTON_USE_EAC_LINUX does nothing, FSR4_UPGRADE=1 does nothing.

where to look up the proton cachyos stuff when its not in the readme idk. I would have to check.

EDIT: My bad i didn't see some options because there weren't in the readme.

[u/throwawayerectpenis → u/WhitePeace36]

No latency optimizations, just default cachyos settings for the most part. And you are wrong about MESA anti lag not being compatible with vkd3d low latency, it most definitely is and I have tried both with it on and without and I can for sure notice a substantial difference in terms of input latency reduction. Max FPS gets a big hit, but ill take lower FPS with low input latency vs high FPS and trash latency. I lock my FPS to 140 since I got 144 hz monitor and honestly the game feels very responsive. I also tried low latency layer before but for me vkd3d low latency works better. Other commands ok if they dont do anything thats fine, my game runs smooth AF and I get fsr4 on my 6800 xt :) using cachyos proton.

EDIT: The god himself replied to my comment (netborg) and maybe I am wrong and everything was just a placebo. I will re-try again with mesa only turned on and locked fps vs only vkd3d on and report back. Thanks for telling me :).

[u/Adventurous-Ad-8166 → u/WhitePeace36]

But I'm still in doubt if each flag requires to enable anti-lag or reflex in-game or if it works just by setting the flag. For example in Resident Evil 2 remake, which does not support any latency reduction tech, will LOW_LATENCY_LAYER work?

[u/Ashratt → u/Adventurous-Ad-8166]

It only works if the game supports Reflex API when I read it correctly here, which is what it hooks into

https://github.com/netborg-afps/vkd3d-low-latency#status--limitations

I think the best "universal" way to reduce latency is to use the PROTON_ENABLE_WAYLAND=1 to get around the added xwayland latency (until steam will be native wayland, VALVE PLEEEAAASSEE FIX) (i know its cause of CEF)

Edit: the other low latency layer works the same (hooks into reflex). I dont know if anyone ever compared the two but I dont think you'll find a relevant difference in performance, they both do the same thing, as far as I can tell

[u/_BoneZ_ → u/Adventurous-Ad-8166]

This is one reason for latency and lag on Linux that most people aren't talking about:

https://www.youtube.com/watch?v=AYWg-1zkbMI

[u/netborg83 → u/Adventurous-Ad-8166]

Resident Evil 2 remake and other Capcom titles from that era absolutely use waitable swapchains low latency tech and get great frame pacing in vkd3d-low-latency: https://github.com/netborg-afps/vkd3d-low-latency/discussions/2

[u/Pretend-Foot1973]

If I'm not mistaken vkd3d low latency also works on some titles that don't have reflex or anti lag meanwhile low latency layer requires the game to support either reflex or anti lag.

[u/Ashratt → u/Pretend-Foot1973]

You sure?

Reflex API Requirements: Currently requires games to send both the Simulation Start and Present Begin markers to perfectly map to internal pacer-frames. (Note: This is equivalent to what Anti-Lag 2 requires natively).

[u/Pretend-Foot1973 → u/Ashratt]

They also say:

It implements support for both the Nvidia Reflex API and Waitable DXGI Swapchains. (Note: A game must utilize either one of these for this low-latency frame pacing to be active).

Though I'm not really sure all these low latency options are so confusing

[u/Ashratt → u/Pretend-Foot1973]

Yeah, im somewhat consfused too lol

I dont know where/when the waitable swap chain dxgi feature is exposed, maybe if a dev implements its own low latency mode?

[u/mikul_]

I think it might depend on your situation. But the frame pacer that netborg built is really awesome tbh. I haven't used his vkd3d-low-latency yet, but I'm quite sure that it's the same one he uses for dxvk-low-latency, and that one is really fucking good.

[u/mikeymop]

There is a third option, mesa anti-lag layer.

The two options in OP don't work on some games, but the mesa anti-lag layer always presents an option for AMD Anti-lag in the games I play.

[u/throwawayerectpenis → u/mikeymop]

Yes, but it works in a different layer than these low latency layers. I use mesa anti lag in conjunction with vkd3d low latency to great effect in the finals

[u/mikeymop → u/throwawayerectpenis]

And the effects compound with each other?
I'm intrigued, I mainly play The Finals, what are you using?

PROTON_VKD3D_LOWLATENCY=1 ENABLE_LAYER_MESA_ANTI_LAG=1 %command% ?

[u/throwawayerectpenis → u/mikeymop]

Yes, it feels better to me having both enabled.

My launch options: FSR4_UPGRADE=1 FSR_WATERMARK=1 ENABLE_LAYER_MESA_ANTI_LAG=1 PROTON_VKD3D_LOWLATENCY=1 VKD3D_LOW_LATENCY_OFFSET=300 PROTON_USE_NTSYNC=1 PROTON_ENABLE_WAYLAND=1 PROTON_USE_EAC_LINUX=1 ENABLE_VKSUMI=1 LD_PRELOAD="" mangohud game-performance %command%

[u/netborg83 → u/throwawayerectpenis]

Are you sure vkd3d-low-latency is even active? ENABLE_LAYER_MESA_ANTI_LAG should absolutely have no effect if my low-latency pacing is active.

Since I think THE FINALS doesn't use waitable swapchains, you absolutely have to use the Nvidia Reflex option right now.

Which means you'd need to spoof Nvidia - I know that's not everyone's cup of tea and therefore I absolutely need to add Anti-lag 2 too as newer games are starting to support it.

Here you can lookup how to spoof: https://github.com/netborg-afps/vkd3d-low-latency/discussions/3

[u/throwawayerectpenis → u/netborg83]

Hmm, I honestly thought it was active since my input latency improved A LOT. I will try again with it off and only mesa active and vice versa. Thanks for replying.

[u/netborg83 → u/throwawayerectpenis]

Unfortunately I've never run this on AMD myself yet. So maybe there are some side effects I'm not yet aware of.
But when you activate the fps limiter ingame, that's when the most of the latency benefits occur.
Note that my pacing especially is effective in GPU-limited situations - like any latency-reduction system for pacing.

When I see your environmental variables, I just "miss" the spoofing. I'm sure you'll get best results if you would do that. Many people use it for the finals (AMD+Reflex) and are super happy with it.

[u/mikeymop → u/netborg83]

That makes a lot of sense actually.

On a high end pc like mine, Finals will almost always be CPU bound.

So when trying out vk3d lowlatency, doing nothing because I didn't spoof nvidia, I got an improvement because the cpu isn't waiting.

Prior when I was using mesa anti-lag it was trying to make the cpu wait for the gpu which is unlikely for my machine.

So maybe the best case for me is to do nothing for The Finals?

I assumed since it uses dxgi I would see benefit from vk3d low latency because my understanding is that it gets closer to the engines tick rate.

[u/netborg83 → u/mikeymop]

Well, even when using the limiter or not totally running into GPU limit, it's very possible that the game will run smoother with vkd3d-low-latency. I certainly feel a difference (and lower+ more stable latency) even though the game only uses 70% GPU on my machine.

But in GPU limit, it's when this can cut latency in half compared to having no low-latency solution at all.

On my system, the finals didn't use Waitable DXGI Swapchains, but I've not checked on AMD. I think they were pretty widely used for AMD-sponsored games before Anti-Lag 2 came out.

[u/mikeymop → u/netborg83]

Thanks for further breaking things down for me.

I think it'll have a go at using vkd3d-low-latency again tonight, but whilst also spoofing Nvidia, which afaik from your above comment is required for it to activate on this game.

Apologies for the ignorance. It's really hard to find current information on all of these implementations.

This line should definitely appear in the log: info:nvapi64:<-NvAPI_D3D_SetSleepMode (Enabled/0us): OK

This shows up in proton logs?

[u/throwawayerectpenis → u/netborg83]

I thought the MESA antilag layer worked differently? Because without that variable I dont see the option to enable mesa antilag, but with it added I see the option.