Special K can drastically reduce latency

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Darktalon
Posts: 13
Joined: 01 Apr 2019, 14:54

Special K can drastically reduce latency

Post by Darktalon » 26 Sep 2020, 16:49

Special K can drastically reduce latency

https://discourse.differentk.fyi/t/topi ... 20/79/1707

Conan
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Joined: 18 May 2020, 06:50

Re: Special K can drastically reduce latency

Post by Conan » 26 Sep 2020, 17:48

can someone elaborate on this?

deama
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Joined: 07 Aug 2019, 12:00

Re: Special K can drastically reduce latency

Post by deama » 26 Sep 2020, 20:43

From reading it, seems like it's a framerate limiter tool, similiar to RTSS, that works as well as the nvidia one, however it does slightly worse with input lag, but has better pacing, so you should get less 1% and 0.1% dips, seems more finnicky to get working though.

https://www.reddit.com/r/pcgaming/comme ... x11_based/
- Frame time consistency-wise, the SpecialK's frame rate limiter was significantly better than both RTSS and NV v3 limiters in all DX11 scenarios, while RTSS and NV v3 were overall on par in terms of frametime stability.

- Approximate latency-wise, the NV v3 limiter was significantly better than both the SpecialK and RTSS limiter in all DX11 scenarios, being the SpecialK limiter better than the RTSS one too.

- However, if we also consider a usability / performance approach between the different FPS limiters, the most balanced and overall recommended option, would be the RTSS limiter instead, which is easier to get working in all games and to be set up vs. the SpecialK limiting method, that is a bit difficult to get working on certain games/clients and it will require to tweak its "Tolerance" setting on per game-basis in some cases to prevent certain instability issues.

- Therefore, based on all the prior data and notes, and when the SpecialK mod is injected succesfully and its limiter is set up properly on a per game-basis, we can clearly state that the SpecialK's frame rate limiter is by far the most consistent and accurate FPS limiting method on DX11-based scenarios. That is, under certain scenarios, the SpecialK limiter can be considered an excellent and recommended alternative to cap your FPS and guarantee the stadiest and smoothest framerate, and specially as a recommended alternative to any suboptimal in-game limiter.

Darktalon
Posts: 13
Joined: 01 Apr 2019, 14:54

Re: Special K can drastically reduce latency

Post by Darktalon » 26 Sep 2020, 23:40

deama wrote:
26 Sep 2020, 20:43
From reading it, seems like it's a framerate limiter tool, similiar to RTSS, that works as well as the nvidia one, however it does slightly worse with input lag, but has better pacing, so you should get less 1% and 0.1% dips, seems more finnicky to get working though.

https://www.reddit.com/r/pcgaming/comme ... x11_based/
- Frame time consistency-wise, the SpecialK's frame rate limiter was significantly better than both RTSS and NV v3 limiters in all DX11 scenarios, while RTSS and NV v3 were overall on par in terms of frametime stability.

- Approximate latency-wise, the NV v3 limiter was significantly better than both the SpecialK and RTSS limiter in all DX11 scenarios, being the SpecialK limiter better than the RTSS one too.

- However, if we also consider a usability / performance approach between the different FPS limiters, the most balanced and overall recommended option, would be the RTSS limiter instead, which is easier to get working in all games and to be set up vs. the SpecialK limiting method, that is a bit difficult to get working on certain games/clients and it will require to tweak its "Tolerance" setting on per game-basis in some cases to prevent certain instability issues.

- Therefore, based on all the prior data and notes, and when the SpecialK mod is injected succesfully and its limiter is set up properly on a per game-basis, we can clearly state that the SpecialK's frame rate limiter is by far the most consistent and accurate FPS limiting method on DX11-based scenarios. That is, under certain scenarios, the SpecialK limiter can be considered an excellent and recommended alternative to cap your FPS and guarantee the stadiest and smoothest framerate, and specially as a recommended alternative to any suboptimal in-game limiter.
That is based off an older version.

This last month Kaldaien (developer of Special K), has made it his personal mission to reduce latency as much as possible.

Special K is now steadier, smoother, AND less latency than any other option.

deama
Posts: 209
Joined: 07 Aug 2019, 12:00

Re: Special K can drastically reduce latency

Post by deama » 27 Sep 2020, 06:43

Darktalon wrote:
26 Sep 2020, 23:40
That is based off an older version.

This last month Kaldaien (developer of Special K), has made it his personal mission to reduce latency as much as possible.

Special K is now steadier, smoother, AND less latency than any other option.
Any tests to back that up though? Something with a high-speed camera comparing RTSS vs special k?

diakou
Posts: 74
Joined: 09 Aug 2020, 11:28

Re: Special K can drastically reduce latency

Post by diakou » 27 Sep 2020, 09:10

deama wrote:
27 Sep 2020, 06:43
Darktalon wrote:
26 Sep 2020, 23:40
That is based off an older version.

This last month Kaldaien (developer of Special K), has made it his personal mission to reduce latency as much as possible.

Special K is now steadier, smoother, AND less latency than any other option.
Any tests to back that up though? Something with a high-speed camera comparing RTSS vs special k?
Unfortunately, none currently, I asked a few friends if they would have the time to help out, but schedules are packed. I'll see if I can get something done.

I personally don't know how much beneficial it is for competitive purposes as I (from pure feel) notice it being worse whenever I engage the low latency mode, drop late frames on my 240hz monitor on a test fighting game I'm playing right now called Rushdown Revolt (keep in mind, this program can make anti-cheat act up, it hooks similarly to RTSS but also manipulates the DirectX DLL's.

I am not very well equipped to talk about it, as only a very few people understand special k a lot more deep down, such as Aemony or Kaldaien himself. I hope that he might come here and provide a quick questions/answers talk.

I would love to see how this program behaves for games that are relatively low latency compared to AAA singleplayer games etc. If it was usable for competitive purposes, it would be incredible.

However there's many incredible benefits to special K, he can retrofit fullscreen exclusive mode for any DX11 game that does not have a fullscreen exclusive mode. So if your game only has borderless window or fake fullscreen, this program can create the correct flip model for it, and it does it with pure perfection. It can also retrofit HDR support into games and many, many more things. It's cool. (and kinda black magic)

diakou
Posts: 74
Joined: 09 Aug 2020, 11:28

Re: Special K can drastically reduce latency

Post by diakou » 27 Sep 2020, 12:27

Double-post but, I think Chief would be interested in seeing some of the capabilities of special k's framerate limiter versus RTSS or Nvidia's limiter, mainly due to how he's talking about framerate limiters very often for perfect framepacing etc.
Chief Blur Buster wrote:
23 Sep 2020, 14:07
I've added a shadow redirect link to the Programming Forum -- because this is of fantastic interest to software developers who are also connoiseurs of latency.

What NVIDIA is doing about latency is really truly fantastic stuff, from Reflex to FrameView.

A link to forum thread The Amazing Human Visible Feats Of The Millisecond was shared inside one of NVIDIA's team, which probably helped inspired to do some of this stuff, amongst a lot of other stuff.
If you have the time, here are the two direct links to "low latency mode" and NVIDIA Driver being compared with Special K (and if you use special k, but then use the NVIDIA Driver framerate limiter, you'll have even less latency) (it's just linking to a discourse forum with the pictures + explanation, it was posted as opening post of this thread)
https://discourse.differentk.fyi/t/topi ... 20/79/1707

Special K vs RTSS 60fps cap in a game called trover (older patch 4 days ago, it's now even more improved as of 2 days ago, lower latency)
https://discourse.differentk.fyi/t/topi ... 0/79/1672

Extreme capframex test with Ori and the will of the whisps capped at 12 fps with RTSS and Special K https://discourse.differentk.fyi/t/topi ... 20/79/1770

Would love to hear some thoughts about this, if you have any at all, I think the Special K owner / designed said optionally he could help implement the way special k does things into RTSS so people wouldn't have to use something they're not familiar with, but he would have a hard time convincing RTSS to implement this without backing from important figures.

a quoted interaction on why special k's framerate limiting methods are powerful:
Aemony:
What’s up with the weird 0.1% percentile FPS of Unlimited and RTSS ? Is Special K just pacing the frames better to prevent such weird drops?
Kaldaien:
That’s the magic of aligning your framerate limiter’s clock to VBLANK :slight_smile: And some pretty nifty clock drift compensation code I designed that sneaks in occasional clock re-syncs only when re-syncing the clock can be done without inducing a hitch.

I basically always stop delaying frames at precisely the same time that the DWM compositor has swapped the front-buffer out and is ready to accept a new frame. Thus when I tell the engine to continue, it can do so with zero back-pressure from pending VSYNC.

We’re not even playing the same game here, RTSS may try to count the frames and limit them but it’s not taking into account the traffic cop that is the DWM. RTSS releases the GPU into oncoming traffic and causes accidents frequently because its clock is not sync’d up with the DWM

You can basically look at any framerate limiting done by RTSS and you will always find this problem. It can count frames, just probably shouldn’t be directing traffic since it’s not paying attention to all the collisions caused by its bad clock.

Darktalon
Posts: 13
Joined: 01 Apr 2019, 14:54

Re: Special K can drastically reduce latency

Post by Darktalon » 27 Sep 2020, 16:11

deama wrote:
27 Sep 2020, 06:43
Darktalon wrote:
26 Sep 2020, 23:40
That is based off an older version.

This last month Kaldaien (developer of Special K), has made it his personal mission to reduce latency as much as possible.

Special K is now steadier, smoother, AND less latency than any other option.
Any tests to back that up though? Something with a high-speed camera comparing RTSS vs special k?
Nvidia is sending him an LDAT so he will be able to use that to prove it, currently CapFrameX is being used as proof.

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axaro1
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Re: Special K can drastically reduce latency

Post by axaro1 » 28 Sep 2020, 06:32

Special K seems incredibly consistent, the framerate standard deviation is ̶1̶0̶x̶ ̶l̶o̶w̶e̶r̶ 7x-5.5x more consistent than RTSS or Nvidia's built in fps limiter, I'll wait for it to get more visibility since I'd rather not get false-flagged and hardware banned for injecting dx11 games.
This may be the end of my preference for engine based frame rate limiters that are known for having less input lag than RTSS/chill but are generally less stable in terms of frametimes.
It's great to see softwares such as CapFrameX being used for these testings.
Last edited by axaro1 on 28 Sep 2020, 08:49, edited 1 time in total.
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RealNC
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Re: Special K can drastically reduce latency

Post by RealNC » 28 Sep 2020, 08:16

axaro1 wrote:
28 Sep 2020, 06:32
Special K seems incredibly consistent, the frametime deviation is 10x lower than RTSS or Nvidia's built in fps limiter
The frametime graph with RTSS is perfectly flat. So how can SK have 10x lower deviation if it's already 0 with RTSS?
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