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Dreamic · 09-02-2022, 06:24 AM

(09-02-2022 03:16 AM)ToastyX Wrote:
(09-02-2022 02:12 AM)Dreamic Wrote: In order to lower my VRR/LFC Range from 80 to 30, changing it is not enough. I must also change the Device ID to something with a lower VRR Range, like DELA179 (Dell/Alienware AW2721D 1-240Hz). Mine is SAM105C (Samsung Odyssey G7 80-240Hz).
This is the only way to go below 80Hz VRR. Reset Device ID to SAM105C and it will no longer go down to 30Hz~.
Also the Nvidia database is wrong about this display being 60-240Hz, it's 80-240Hz.
Everything is as up to date as it could be, monitor firmware included.
That means NVIDIA must have ranges hard-coded in the driver for some monitors, possibly to work around issues like flickering. Does the ID need to be a monitor with VRR, or can it be any other random ID?

It can be any random ID, I just checked. It has to be a real manufacturer for CRU to let me click OK though, so I did SAM6666 which isn't a real monitor and my changes work. So it must be in the driver yes. I don't have any issues from doing this, I'm doing it to work around an issue that is flickering basically.

Obviously if I set the limit too low, issues will start to appear and get worse the lower you go, like flickering. Setting the limit to 30Hz makes LFC kick in around 39Hz or 39fps, where you will then be running 78Hz. At 40fps, 40Hz. I start seeing issues more around 35Hz and below, which would require me to set a limit of 25Hz~ or lower. Also playing games at this low of a framerate is not something I would do and already an unpleasant experience, but having to maintain above 80fps, higher actually as LFC kicks in above that, so lets say 90fps minimum, or my Hz will go from 90Hz to 178Hz if I drop to 89fps, there are visible brightness changes when this happens, flicker. Many games are comfortably playable down to far lower than this, LFC should not kick in until you drop below at least 60fps. These drastic Hz jumps are visible, doubling and halving. You want to minimize or eliminate how often it happens.

(09-02-2022 04:36 AM)aelius Wrote:
(09-02-2022 02:12 AM)Dreamic Wrote: I don't think it's a fault of your program but something dumb Nvidia is doing and I think should be added to the Editing VRR Range section, not sure if there's been discussion about this.

In order to lower my VRR/LFC Range from 80 to 30, changing it is not enough. I must also change the Device ID to something with a lower VRR Range, like DELA179 (Dell/Alienware AW2721D 1-240Hz). Mine is SAM105C (Samsung Odyssey G7 80-240Hz).
This is the only way to go below 80Hz VRR. Reset Device ID to SAM105C and it will no longer go down to 30Hz~.
Also the Nvidia database is wrong about this display being 60-240Hz, it's 80-240Hz.
Everything is as up to date as it could be, monitor firmware included.

I don't think everyone will figure this out, why their 40fps in GSync Pendulum is 80Hz instead of 40Hz or 70fps is 140Hz, it's because of Device ID, LFC doubling isn't changed unless Device ID is to a correct one.
And we know LFC on certain displays, I think I've heard mainly VA, results in a brightness shift/flicker, as Hz jumps from 75Hz to 150Hz etc when you drop to 75fps, 85fps will be back at 85Hz. This is how you fix/mitigate this.

Increasing the variable refresh range to dip down into 30Hz is a really bad idea, because the pixel response time and input lag will skyrocket, and if you ever dip below 30Hz the flicker will be way WORSE than before. There's a reason stock LFC kicks on as high as 80Hz.

A better approach is to shrink the variable refresh range. Flicker becomes harder to notice in the higher Hz, so you can leverage your 240Hz of headroom to make the range 120Hz-240Hz. Be sure to make it exactly 1/2 of the actual max Hz (239.something). You can go even smaller, if you like, but you'll create a gap in the coverage. A range of 150Hz-240Hz won't be able to engage variable refresh from 121fps-150fps, for example.

fwiw, flicker should only ever occur if you've got poor frame pacing, so the easiest fix is always to investigate why the game is running poorly. Many games are just unfixable though

You would agree with me if you were seeing what I'm seeing. The pixel response and input lag of this display are more than good enough 30-60Hz, and I won't dip low enough to engage LFC. Stock LFC being as high as 80Hz is rare, almost everything else is a good bit lower. I can still notice flicker too much in high Hz, I've thought about changing the range around higher like you're saying but for this display what I'm doing is a better solution. Lastly it's not poor frame pacing, it's LFC flicker, from engage and disengaging, doubling and halving your Hz up and down if you're hovering around and crossing the threshold one way then the other repeatedly, these doubling and halving of Hz fluctuations are very visible. Without LFC, your Hz up and down is just the same as your framerate up and down, you're not usually going from 80fps to 160fps in a millisecond etc. My understanding is this issue is more noticeable on VA VRR displays as well, maybe it's better with IPS etc, the brightness/flicker from huge Hz jumps.

aelius · (Last edited: 09-02-2022, 12:24 PM by aelius)

(09-02-2022 06:24 AM)Dreamic Wrote: The pixel response and input lag of this display are more than good enough 30-60Hz

I won't argue the point if you feel this within your threshold of pain, but I urge other readers to not go in this direction.

(09-02-2022 06:24 AM)Dreamic Wrote: Stock LFC being as high as 80Hz is rare, almost everything else is a good bit lower.

Other monitors have different characteristics.

(09-02-2022 06:24 AM)Dreamic Wrote: Lastly it's not poor frame pacing, it's LFC flicker, from engage and disengaging

Yes, I forgot to mention this, but only because in this scenario it's even easier and much wiser to simply frame limit around the LFC on/off threshold. With the monitor in stock configuration, if you can't keep a game over 80fps consistently then limit it to 75fps and you've solved the problem.

Changing the variable refresh range lets you play with where you'd need to set your frame limit; if you've got a decently beefy PC it might be desirable to have the range around 105Hz-240Hz for example, such that you can target 120fps (or higher) in lighter games, and frame limit heavier games at 100fps.

(09-02-2022 06:24 AM)Dreamic Wrote: My understanding is this issue is more noticeable on VA VRR displays as well, maybe it's better with IPS etc, the brightness/flicker from huge Hz jumps.

I don't know if it's /more/ noticeable on VA, but it certainly is noticeable on basically any kind of display, even OLED.

Good luck finding the solution that fits you best.

Dreamic · (Last edited: 09-03-2022, 03:28 AM by Dreamic)

(09-02-2022 12:11 PM)aelius Wrote:
(09-02-2022 06:24 AM)Dreamic Wrote: The pixel response and input lag of this display are more than good enough 30-60Hz

I won't argue the point if you feel this within your threshold of pain, but I urge other readers to not go in this direction.

Pixel response and input lag are worse or better at a refresh rate depending on monitor, some are worse, some are better. LFC engage/disengage/flicker is far worse of a problem on this monitor.

(09-02-2022 12:11 PM)aelius Wrote:
(09-02-2022 06:24 AM)Dreamic Wrote: Stock LFC being as high as 80Hz is rare, almost everything else is a good bit lower.

Other monitors have different characteristics.

There is nothing worse about this monitor below 80Hz. Flickering also does not begin until about 35Hz, which would require setting a limit of 25Hz~, as LFC kicks in roughly 10Hz/fps above. Nobody plays or wants to play games at this low framerate anyway.

(09-02-2022 12:11 PM)aelius Wrote:
(09-02-2022 06:24 AM)Dreamic Wrote: Lastly it's not poor frame pacing, it's LFC flicker, from engage and disengaging

Yes, I forgot to mention this, but only because in this scenario it's even easier and much wiser to simply frame limit around the LFC on/off threshold. With the monitor in stock configuration, if you can't keep a game over 80fps consistently then limit it to 75fps and you've solved the problem.

Changing the variable refresh range lets you play with where you'd need to set your frame limit; if you've got a decently beefy PC it might be desirable to have the range around 105Hz-240Hz for example, such that you can target 120fps (or higher) in lighter games, and frame limit heavier games at 100fps.

I have a 3080 and 5800x, a game like Cyberpunk 2077 maxed out can drop into the 50's, 1440p. I could set the limit to 120-240Hz but I don't think that would even always keep me in LFC mode as I'm sure it goes above 120fps sometimes, I'd have to cap framerate... and then I have to go into CRU to change limit when I want to play another game that isn't always above or below 120fps...
You want to always have LFC engaged, or always have it disengaged.
Not engaging and disengaging while you're playing a game, at least on this monitor.

Avoid instantaneous doubling and halving of Hz.
I guess other people can adjust their framerate caps and lower/raise their VRR/LFC floor on a game by game basis if that's not beyond inconvenient to them...

aelius · 09-03-2022, 05:57 AM

Suit yourself

DShpak · 09-03-2022, 06:05 AM

Will CRU work if my laptop has only built-in intel uhd 620 graphics? In my case additional resolutions created by CRU don't show up in the Windows 11 settings. Please tell me what to do in this case?

Dreamic · (Last edited: 09-03-2022, 12:50 PM by Dreamic)

(09-03-2022 05:57 AM)aelius Wrote: Suit yourself

Maybe as games get more demanding in time and my PC is averaging lower framerates below 120fps in demanding games this will be more appealing, but otherwise I don't know if capping below is worth it if I would be playing a game that could be shooting up to 160fps/Hz+ sometimes for example. For such a game that averages mid-100's I would need to lower the 120-240 for the times it drops below 120fps.

Anyways your ideal solution is pretty much if most of the demanding games you play average below 120fps, and then the only other things you play are like eSports titles like Valorant, CSGO, etc that will always be 240fps+, set V rate to 119-240 (cause you can't do exactly half/decimals in CRU, actual rate is 239.957Hz half = 119.9785Hz) and then FPS limit at 115/116~.

Maybe I'll do it when all the new games I'm playing are averaging below that, if I'm not upgrading my PC. A good 360Hz monitor for a 180Hz limit or something would be nicer. If we hypothetically scaled things differently, you wouldn't cap a 60Hz monitor at 30Hz/29fps if you could get up to 45fps sometimes with VRR. But yes 30 to 45 is more noticeable than 120 to 180... I think the extra framerate 120+ if it happens often enough is probably more important than the pixel response. 180fps at 180Hz is better than 120fps at 240Hz in my opinion. Anyways I don't have anything more to contribute, I see the Device ID thing was added to the VRR section of the first post.

***ToastyX*** · 09-03-2022, 02:32 PM

(09-03-2022 06:05 AM)DShpak Wrote: Will CRU work if my laptop has only built-in intel uhd 620 graphics? In my case additional resolutions created by CRU don't show up in the Windows 11 settings. Please tell me what to do in this case?

Yes, but possibly for external displays only. Intel seems to be restricting laptop screens for some reason.

mdrejhon · (Last edited: 09-07-2022, 12:06 AM by mdrejhon)

(09-02-2022 06:24 AM)Dreamic Wrote: Stock LFC being as high as 80Hz is rare, almost everything else is a good bit lower.

(09-03-2022 03:21 AM)Dreamic Wrote: There is nothing worse about this monitor below 80Hz. Flickering also does not begin until about 35Hz, which would require setting a limit of 25Hz~, as LFC kicks in roughly 10Hz/fps above. Nobody plays or wants to play games at this low framerate anyway.

LFC flicker is caused by pixel decay on the LCD, since a pixel fades to its rest state when not refreshed for too long.

Different panels have fast-fade behavior and others slower-fade.

That's why I recommend to many people to manually edit min Hz to a higher number to prevent display flicker -- but not all displays require that. LFC stutter penalty is linked to max Hz, so it is extremely minor when the VRR range is wide (e.g. 240Hz).

For example, compare a 120Hz FreeSync monitor to a 280Hz FreeSync monitor -- a 0.5/280sec error margin (stutter) is extremely invisible compared to a 0.5/120sec error margin. So the higher your max Hz, I recommend a higher min Hz as long as (min,max) is about 3x or thereabouts.

LFC is a software-based mechanism (driver-initiated refresh cycles) in generic VRR implementations. Also, NVIDIA drivers (in G-SYNC Comaptible mode) sometimes override the LFC min-Hz and arbitrarily choose a higher LFC min Hz, at least in a 'sticky' manner. So if framerate falls a lot to trigger LFC, framerates need to rise a lot before LFC automatically disables. AMD drivers have a different LFC-stickiness/stiction algorithm.

You can watch this via the monitor's OSD framerate counter (more accurately refresh cycle counter), since this number will suddenly double or triple when LFC is initiated, so real GPU 35fps would read as 70fps in the monitor's framerate counter (which I prefer would have been named "refresh cycle counter") Try AMD, try NVIDIA, you'll see different LFC algorithms running.

Dreamic · 09-07-2022, 03:15 AM

(09-07-2022 12:03 AM)mdrejhon Wrote:
(09-02-2022 06:24 AM)Dreamic Wrote: Stock LFC being as high as 80Hz is rare, almost everything else is a good bit lower.

(09-03-2022 03:21 AM)Dreamic Wrote: There is nothing worse about this monitor below 80Hz. Flickering also does not begin until about 35Hz, which would require setting a limit of 25Hz~, as LFC kicks in roughly 10Hz/fps above. Nobody plays or wants to play games at this low framerate anyway.

LFC flicker is caused by pixel decay on the LCD, since a pixel fades to its rest state when not refreshed for too long.

Different panels have fast-fade behavior and others slower-fade.

That's why I recommend to many people to manually edit min Hz to a higher number to prevent display flicker -- but not all displays require that. LFC stutter penalty is linked to max Hz, so it is extremely minor when the VRR range is wide (e.g. 240Hz).

For example, compare a 120Hz FreeSync monitor to a 280Hz FreeSync monitor -- a 0.5/280sec error margin (stutter) is extremely invisible compared to a 0.5/120sec error margin. So the higher your max Hz, I recommend a higher min Hz as long as (min,max) is about 3x or thereabouts.

LFC is a software-based mechanism (driver-initiated refresh cycles) in generic VRR implementations. Also, NVIDIA drivers (in G-SYNC Comaptible mode) sometimes override the LFC min-Hz and arbitrarily choose a higher LFC min Hz, at least in a 'sticky' manner. So if framerate falls a lot to trigger LFC, framerates need to rise a lot before LFC automatically disables. AMD drivers have a different LFC-stickiness/stiction algorithm.

You can watch this via the monitor's OSD framerate counter (more accurately refresh cycle counter), since this number will suddenly double or triple when LFC is initiated, so real GPU 35fps would read as 70fps in the monitor's framerate counter (which I prefer would have been named "refresh cycle counter") Try AMD, try NVIDIA, you'll see different LFC algorithms running.

I do watch Hz in OSD during Pendulum demo and 80-240Hz is jarring when brightness flickers/fluctuates from LFC engaging/disengaging.

So either I lower it so LFC never engages, or raise it (120Hz max) and cap FPS so it doesn't exceed/disengage LFC, which isn't ideal for all games.
Or I raise it and don't cap and deal with less worse brightness flicker/fluctuation from LFC.

I'd like to not deal with any brightness flicker/fluctuation.

This is the type of thing I'm talking about:
https://youtu.be/XDWOHT5qrI8
Dreadful.
Doesn't capture it perfectly but look at all the shadows and darkness in the background etc, the color tone/brightness of the sand etc I can also see change which maybe isn't picked up as well in this video.
No thank you.
It's like there's lightning going off behind the camera in the Pendulum demo.

Bigapps1206 · (Last edited: 09-08-2022, 07:16 PM by Bigapps1206)

Hi ToastyX. I'm trying to use CRU to set a 640x480 resolution on my Mitsubishi 930sb CRT monitor. Whenever I add it in CRU it does not show up in Nvidia control panel but my other 1200x1600 resolution does. I use the CRT timings drop-down and has tried multiple refresh rates to see if that would change anything.

If I create a custom 640x480 resolution in Nvidia control panel itself it will let me apply it and work fine but as soon as I turn the system off, turn either monitor off or change the resolution back up. The custom resolution disappears and I cannot recreate it until I cycle the whole computer.

I'm using a 30 series GPU with a display port to vga adapter if that important

Thank you in advanced toasty, love the programme!