LDAT Tested: Reflex Auto FPS Limiter Input Lag vs. In-game & External FPS Limiters

Talk about NVIDIA G-SYNC, a variable refresh rate (VRR) technology. G-SYNC eliminates stutters, tearing, and reduces input lag. List of G-SYNC Monitors.
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jorimt
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LDAT Tested: Reflex Auto FPS Limiter Input Lag vs. In-game & External FPS Limiters

Post by jorimt » 26 Sep 2021, 23:39

I've been getting multiple visitors in the G-SYNC 101 comments section asking whether the Reflex auto FPS limit has the same input lag as the in-game limiter due to the fact that it's also implemented by the devs at the engine level, so I managed to squeeze in some casual LDAT testing over the weekend.

It had originally been assumed (at least by me) that Reflex used Nvidia's Max Frame Rate limiter, but according to the below results, that may not be the case, at least in Overwatch...

Test Information (full PC specs in forum sig):

- Monitor: PG279QM (240Hz, Native G-SYNC)
- NVCP Settings: G-SYNC on + NVCP V-SYNC on
- Game Settings: Overwatch (Maxed, Reduced Buffering On, No GPU limitation)
- Test Device: Nvidia LDAT using Overwatch "Flash Indicator" setting for consistency w/40 samples per scenario (results rounded and min/max values omitted for simplicity/time)

Results:

237 FPS in-game limit:
16ms

VS.

No limiter (240+ FPS reverting to V-SYNC behavior):
24ms (+8ms = nearly 2 frames more than in-game)

224 Reflex auto limit:
16ms (virtually the same as in-game)

224 FPS Low Latency "Ultra" auto limit:
19ms (+3ms = over 1/2 frame more than in-game)

237 FPS Nvidia Max Frame Rate manual limit:
18ms (+2ms = 1/2 frame more than in-game)

237 FPS RTSS (async) manual limit:
18ms (+2ms = 1/2 frame more than in-game)

There you have it; as far as Overwatch is concerned, and when tested with an LDAT, the Reflex auto limiter does not increase frame delay over the in-game limiter. RTSS and MFR are no slouches either, at only a 1/2 frame increase over in-game and Reflex.

As for ULLM having slightly higher frame delay than RTSS and MFR on average, it could be error margin, could be within test-to-test variance, could be due to the MPRF "1" component in a non-GPU-bound scenario, could be something else. Not sure, and I don't really care at the moment since Reflex is its replacement in this game anyway (no reason to use it over that or the others, and Reflex would override it when both are enabled).

Anyway, I may update the OP over time (no ETA) with tests for the other Reflex-supported games I own for further data and/or confirmation on the above, but leaving this here for now...

--------

EDIT #1 (09/27/2021): Updated the thread title for clarity.
(jorimt: /jor-uhm-tee/)
Author: Blur Busters "G-SYNC 101" Series

Displays: ASUS PG27AQN, LG 48CX VR: Beyond, Quest 3, Reverb G2, Index OS: Windows 11 Pro Case: Fractal Design Torrent PSU: Seasonic PRIME TX-1000 MB: ASUS Z790 Hero CPU: Intel i9-13900k w/Noctua NH-U12A GPU: GIGABYTE RTX 4090 GAMING OC RAM: 32GB G.SKILL Trident Z5 DDR5 6400MHz CL32 SSDs: 2TB WD_BLACK SN850 (OS), 4TB WD_BLACK SN850X (Games) Keyboards: Wooting 60HE, Logitech G915 TKL Mice: Razer Viper Mini SE, Razer Viper 8kHz Sound: Creative Sound Blaster Katana V2 (speakers/amp/DAC), AFUL Performer 8 (IEMs)

disq
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Re: LDAT Tested: Reflex Auto FPS Limiter Input Lag vs. In-game & External FPS Limiters

Post by disq » 27 Sep 2021, 14:55

How come this doesn't have any reply so far?! 🤔

Really appreciate this type of info jorimt, hopefully we see other games soon, although i'm sure the outcome will be identical :)

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Re: LDAT Tested: Reflex Auto FPS Limiter Input Lag vs. In-game & External FPS Limiters

Post by jorimt » 27 Sep 2021, 15:08

disq wrote:
27 Sep 2021, 14:55
How come this doesn't have any reply so far?! 🤔
I'm not expecting any immediate traffic. This thread was more intended for reference/linking when I see future visitors asking about this on the forums and in the G-SYNC 101 comments section ;)
disq wrote:
27 Sep 2021, 14:55
although i'm sure the outcome will be identical :)
That's my current guess as well; it's highly likely implementation is the same across Reflex-supported games in the respect, but when I get the time, I will corroborate with a couple other supported titles for thoroughness sake.
(jorimt: /jor-uhm-tee/)
Author: Blur Busters "G-SYNC 101" Series

Displays: ASUS PG27AQN, LG 48CX VR: Beyond, Quest 3, Reverb G2, Index OS: Windows 11 Pro Case: Fractal Design Torrent PSU: Seasonic PRIME TX-1000 MB: ASUS Z790 Hero CPU: Intel i9-13900k w/Noctua NH-U12A GPU: GIGABYTE RTX 4090 GAMING OC RAM: 32GB G.SKILL Trident Z5 DDR5 6400MHz CL32 SSDs: 2TB WD_BLACK SN850 (OS), 4TB WD_BLACK SN850X (Games) Keyboards: Wooting 60HE, Logitech G915 TKL Mice: Razer Viper Mini SE, Razer Viper 8kHz Sound: Creative Sound Blaster Katana V2 (speakers/amp/DAC), AFUL Performer 8 (IEMs)

diakou
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Re: LDAT Tested: Reflex Auto FPS Limiter Input Lag vs. In-game & External FPS Limiters

Post by diakou » 06 Oct 2021, 16:57

jorimt wrote:
27 Sep 2021, 15:08
disq wrote:
27 Sep 2021, 14:55
How come this doesn't have any reply so far?! 🤔
I'm not expecting any immediate traffic. This thread was more intended for reference/linking when I see future visitors asking about this on the forums and in the G-SYNC 101 comments section ;)
disq wrote:
27 Sep 2021, 14:55
although i'm sure the outcome will be identical :)
That's my current guess as well; it's highly likely implementation is the same across Reflex-supported games in the respect, but when I get the time, I will corroborate with a couple other supported titles for thoroughness sake.
I can help slightly with that, reflex implementation is pretty much exactly the same across the different games except that NVIDIA's provided Reflex Frame Rate Limiter is optional. A game can decide to use their own framerate limiter or Reflex's (I am not talking about Reflex's autocapping behavior - but an actual alternate framerate limiter. The autocapping behavior is unavoidable outside of Fastsync/V-Sync off with VRR & it requires the game to be flagged to allow tearing in DWM or else it'll still autocap even in a v-sync off scenario.)

I'm sure their limiter is probably better than most developers implementations - very unsure what devs are using that limiter over their own, I'd hope most are. Only case I've witnessed where Reflex support isn't outright the best is when Special K is involved. Special K's framerate limiter with Reflex is incredible. (Special K can backport Reflex into any title in d3d11, even d3d12.) It can also do it for d3d9, but it requires utilizing a wrapper like DgVoodoo 2 to wrap from d3d9->d3d11. It's a bit hard to get setup in that specific scenario however.

Reflex SDK also doesn't really need to be changed for whenever an update strikes as it's built in to NvAPI. So I.E when reflex SDK 1.5 came with Image

This became available to all players the moment they upgraded their drivers to 471.11 (no game dev work) for the slightest of change:
Image

P.S - the tests you ran were greatly appreciated, having concrete numbers is great these days, especially for cross-checking behavior and in general, less misinformation spread.

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Re: LDAT Tested: Reflex Auto FPS Limiter Input Lag vs. In-game & External FPS Limiters

Post by jorimt » 06 Oct 2021, 22:21

diakou wrote:
06 Oct 2021, 16:57
I can help slightly with that, reflex implementation is pretty much exactly the same across the different games except that NVIDIA's provided Reflex Frame Rate Limiter is optional. A game can decide to use their own framerate limiter or Reflex's (I am not talking about Reflex's autocapping behavior - but an actual alternate framerate limiter.
Interesting...I had a suspicion something like that might be the case, which is one of the reasons I want to test a few more Reflex-capable games to see if any differences show in the numbers due to this.

The last I had checked Warzone's in-game limiter was before it had Reflex implemented, and it was all over the place. But recently a commenter on my article said it was no longer having any issue staying at the value it was limited to (it used to drift). Perhaps they replaced theirs with the Reflex limiter in this case.
diakou wrote:
06 Oct 2021, 16:57
Reflex SDK also doesn't really need to be changed for whenever an update strikes as it's built in to NvAPI. So I.E when reflex SDK 1.5 came with Image

This became available to all players the moment they upgraded their drivers to 471.11 (no game dev work) for the slightest of change:
Image
Good to know.
diakou wrote:
06 Oct 2021, 16:57
P.S - the tests you ran were greatly appreciated, having concrete numbers is great these days, especially for cross-checking behavior and in general, less misinformation spread.
Thanks, though these tests were super casual (my day job keeps me too busy to even get close to the level of testing that went into the G-SYNC article).

I left out the min and max values, for one, and while it didn't change the averages, I was actually seeing slightly higher maximum readings with the in-game 237 limit vs the Reflex auto limit, at least in the single runs I did per. It would take more to confirm anything in that respect.

That said, this does confirm Reflex isn't worse than the in-game limiter latency-wise, at least where Overwatch is directly concerned, and I'm sure I'll find similar in other Reflex games eventually.

And oh, on a side note, my PG279QM does have the latency analyzer built-in, but compared to the LDAT, it doesn't seem to be nearly as consistent in like-for-like test scenarios. Probably partly due to the former's real mouse factor required (debounce, etc) vs the latter's built-in auto "click" emulation (though I'm sure the LDAT is superior for many other reasons as well).
(jorimt: /jor-uhm-tee/)
Author: Blur Busters "G-SYNC 101" Series

Displays: ASUS PG27AQN, LG 48CX VR: Beyond, Quest 3, Reverb G2, Index OS: Windows 11 Pro Case: Fractal Design Torrent PSU: Seasonic PRIME TX-1000 MB: ASUS Z790 Hero CPU: Intel i9-13900k w/Noctua NH-U12A GPU: GIGABYTE RTX 4090 GAMING OC RAM: 32GB G.SKILL Trident Z5 DDR5 6400MHz CL32 SSDs: 2TB WD_BLACK SN850 (OS), 4TB WD_BLACK SN850X (Games) Keyboards: Wooting 60HE, Logitech G915 TKL Mice: Razer Viper Mini SE, Razer Viper 8kHz Sound: Creative Sound Blaster Katana V2 (speakers/amp/DAC), AFUL Performer 8 (IEMs)

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Re: LDAT Tested: Reflex Auto FPS Limiter Input Lag vs. In-game & External FPS Limiters

Post by Crazyness » 07 Oct 2021, 12:15

i have a couple of questions..

when is d best time 2 use Special K?

when G-Free sync is active?

and can it be used at d same time as afterburner?
any conflicts?

also if i understand it corectly,special k can implement Reflex into any game?
so if a game doesnt have native reflex support,with special k can be inserted into any game we choose 2 play?

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Re: LDAT Tested: Reflex Auto FPS Limiter Input Lag vs. In-game & External FPS Limiters

Post by jmogaming » 05 Nov 2022, 23:59

Hello,

I just recently found your website and joined. This thread covers pretty close to what I was having questions about.
With Modern Warfare 2 just releasing, looking to get the most out of my hardware.
I followed the optimal settings here: https://blurbusters.com/gsync/gsync101- ... ttings/14/

1) Some sources I see suggest to handle max frame rates in game, in the NVCP, or both. Is there a correct answer?

2) The Low Latency Mode in NVCP I set to ultra. I turned it OFF in game for Modern Warfare 2 because it limits FPS to 138 it seemed. Is this correct to get things moving towards 240fps and best input lag?

DISPLAYS: ASUS ROG PG258Q, and PG279
OS: Windows 11
MB: ASUS Z590 Prime-A
CPU: i7-11700k
GPU: Gigabyte 3090
RAM: 32GB G.Skill Ripjaws V (set to 3066MHz)

Thanks!
JMo

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Re: LDAT Tested: Reflex Auto FPS Limiter Input Lag vs. In-game & External FPS Limiters

Post by jorimt » 06 Nov 2022, 09:59

jmogaming wrote:
05 Nov 2022, 23:59
1) Some sources I see suggest to handle max frame rates in game, in the NVCP, or both. Is there a correct answer?
Depends on the user's priorities and goals, as well as the traits of the particular game.

Typically, in-game limiters (including Reflex) are lower latency than external limiters such as RTSS or Nvidia MFR, but the latter tend to have steadier frametime performance.
jmogaming wrote:
05 Nov 2022, 23:59
2) The Low Latency Mode in NVCP I set to ultra. I turned it OFF in game for Modern Warfare 2 because it limits FPS to 138 it seemed. Is this correct to get things moving towards 240fps and best input lag?
LLM is not supported in DX12 or Vulkan games, even when activated. And even where it is, if the game in question supports Reflex and has it enabled, it will override LLM anyway, as Reflex is considered its replacement.
(jorimt: /jor-uhm-tee/)
Author: Blur Busters "G-SYNC 101" Series

Displays: ASUS PG27AQN, LG 48CX VR: Beyond, Quest 3, Reverb G2, Index OS: Windows 11 Pro Case: Fractal Design Torrent PSU: Seasonic PRIME TX-1000 MB: ASUS Z790 Hero CPU: Intel i9-13900k w/Noctua NH-U12A GPU: GIGABYTE RTX 4090 GAMING OC RAM: 32GB G.SKILL Trident Z5 DDR5 6400MHz CL32 SSDs: 2TB WD_BLACK SN850 (OS), 4TB WD_BLACK SN850X (Games) Keyboards: Wooting 60HE, Logitech G915 TKL Mice: Razer Viper Mini SE, Razer Viper 8kHz Sound: Creative Sound Blaster Katana V2 (speakers/amp/DAC), AFUL Performer 8 (IEMs)

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