Some Freesync Questions

Talk about AMD's FreeSync and VESA AdaptiveSync, which are variable refresh rate technologies. They also eliminate stutters, and eliminate tearing. List of FreeSync Monitors.
lc155
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Some Freesync Questions

Post by lc155 » 30 Jun 2020, 21:39

Hi,

To preface, I have been ignorant of the Freesync/high refresh rate world as I have used a standard 60Hz 1440p display up until now. I have tried to do some reading into it, but damn, it seems quite involved to get things working properly, especially on a per-game basis, it seems.

I'm currently planning on grabbing the LG 38GN850, as I wanted a big upgrade in all aspects (size, resolution, refresh rate) but it also leaves me with some questions regarding how certain situations will work. I have seen Chief Blur Buster respond to some of these types of questions before so it would be great if he could weigh in.

First: The 38GN has a G-Sync Compatible range (will be using Nvidia) of 48-144/160Hz, but also mentions LFC. I had no idea what that is, and from my research it appears to mimic what the G-Sync modules did: below 48Hz, it will use frame doubling/tripling in order to bring the monitor back up into VRR range, correct? In short, this panel should *always* have VRR activated?

Second: Does G-Sync Compatible VRR work in windowed modes, or does it need dedicated full screen to work properly?

And now, for the more esoteric usage: Emulators. From what I've read, the majority of emulators do not readily support VRR out of the box (Retroarch seems to do at least), so VRR would have to be forced, I'm presuming? Let's take a specific example: Dolphin.

Some games run at 30fps, some at 60fps. Some even at 50fps for select PAL titles. For the 30fps games, with my above understanding of LFC, then VRR should be activated while playing those titles, correct? And if so, do I still need to configure my monitor refresh rate to frame double (so 120Hz on 60Hz output from the emulator, or 100/150Hz from 50Hz output) every time I want to emulate a game, since 144Hz doesn't divide cleanly? It all gets a bit confusing. Having to change refresh rate every time would get a bit tiresome as well. I'd do it if there was no other option, but just wondering.

For the games which run with very esoteric frame rates of something like 59.7fps, I remember reading something about how G-Sync was a very useful tool in managing to smooth the juddering from those games out, due to the monitor being able to match those uneven frames. Is this something Freesync is able to do as well? I only read it in the context of G-Sync, so just wanted to be sure. I am unsure if the issue with these games was the uneven frame rates or the inconsistent frame times.

Thanks, I hope it made sense.

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jorimt
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Re: Some Freesync Questions

Post by jorimt » 30 Jun 2020, 22:18

lc155 wrote:
30 Jun 2020, 21:39
it seems quite involved to get things working properly, especially on a per-game basis, it seems.
Not necessarily. General recommendation for 100% tear-free G-SYNC is:
G-SYNC on + V-SYNC on (NVCP) + V-SYNC off (in-game) + LLM "On" + minimum -3 FPS in-game or external FPS limit.
lc155 wrote:
30 Jun 2020, 21:39
First: The 38GN has a G-Sync Compatible range (will be using Nvidia) of 48-144/160Hz, but also mentions LFC. I had no idea what that is, and from my research it appears to mimic what the G-Sync modules did: below 48Hz, it will use frame doubling/tripling in order to bring the monitor back up into VRR range, correct? In short, this panel should *always* have VRR activated?
Unlike native G-SYNC, G-SYNC Compatible does LFC it at the driver-level, but yes, they should be comparable, and yes, it means an effective 0 to max Hz VRR range.
lc155 wrote:
30 Jun 2020, 21:39
Second: Does G-Sync Compatible VRR work in windowed modes, or does it need dedicated full screen to work properly?
It works, but the frametime peformance can be poorer than exclusive fullscreen. It's spotty, and sometimes changes behavior from Windows OS updates and/or Nvidia drivers.
lc155 wrote:
30 Jun 2020, 21:39
And now, for the more esoteric usage: Emulators. From what I've read, the majority of emulators do not readily support VRR out of the box (Retroarch seems to do at least), so VRR would have to be forced, I'm presuming? Let's take a specific example: Dolphin.
It's pretty easy to get it working in the likes of RetroArch, for instance, and as for Dolphin, last time I checked, I don't think there was anything particular you had to do to get VRR working.
lc155 wrote:
30 Jun 2020, 21:39
Some games run at 30fps, some at 60fps. Some even at 50fps for select PAL titles. For the 30fps games, with my above understanding of LFC, then VRR should be activated while playing those titles, correct?
Yes.
lc155 wrote:
30 Jun 2020, 21:39
And if so, do I still need to configure my monitor refresh rate to frame double (so 120Hz on 60Hz output from the emulator, or 100/150Hz from 50Hz output) every time I want to emulate a game, since 144Hz doesn't divide cleanly? It all gets a bit confusing. Having to change refresh rate every time would get a bit tiresome as well. I'd do it if there was no other option, but just wondering.

For the games which run with very esoteric frame rates of something like 59.7fps, I remember reading something about how G-Sync was a very useful tool in managing to smooth the juddering from those games out, due to the monitor being able to match those uneven frames. Is this something Freesync is able to do as well? I only read it in the context of G-Sync, so just wanted to be sure. I am unsure if the issue with these games was the uneven frame rates or the inconsistent frame times.
G-SYNC will take care of this automatically. That's what it's made for; matching the refresh rate to the framerate. "Clean" division isn't required, as it can adjust the refresh rate at the decimal level during variable or fixed FPS within the refresh rate.

That said, G-SYNC only fixes V-SYNC-induced stutter, it can't fix system-side stutter, so if the given game has innately poor frame pacing, G-SYNC won't mask or smooth it over, but will instead show it accurately, as it can only reflect what the system is outputting.
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lc155
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Re: Some Freesync Questions

Post by lc155 » 01 Jul 2020, 10:38

jorimt wrote:
30 Jun 2020, 22:18
lc155 wrote:
30 Jun 2020, 21:39
it seems quite involved to get things working properly, especially on a per-game basis, it seems.
Not necessarily. General recommendation for 100% tear-free G-SYNC is:
G-SYNC on + V-SYNC on (NVCP) + V-SYNC off (in-game) + LLM "On" + minimum -3 FPS in-game or external FPS limit.
Well, for someone who is coming from a 60Hz display where I just set the vsync on and away I go, that is quite a bit more daunting when first looking at it. Hopefully in practice it becomes second nature.
jorimt wrote:
30 Jun 2020, 22:18
lc155 wrote:
30 Jun 2020, 21:39
First: The 38GN has a G-Sync Compatible range (will be using Nvidia) of 48-144/160Hz, but also mentions LFC. I had no idea what that is, and from my research it appears to mimic what the G-Sync modules did: below 48Hz, it will use frame doubling/tripling in order to bring the monitor back up into VRR range, correct? In short, this panel should *always* have VRR activated?
Unlike native G-SYNC, G-SYNC Compatible does LFC it at the driver-level, but yes, they should be comparable, and yes, it means an effective 0 to max Hz VRR range.
Excellent. As long as the results deliver, that's all that matters to me.
jorimt wrote:
30 Jun 2020, 22:18
lc155 wrote:
30 Jun 2020, 21:39
Second: Does G-Sync Compatible VRR work in windowed modes, or does it need dedicated full screen to work properly?
It works, but the frametime peformance can be poorer than exclusive fullscreen. It's spotty, and sometimes changes behavior from Windows OS updates and/or Nvidia drivers.
I see. I'm used to using borderless fullscreen due to my habit of tabbing out of games quite often. Dedicated fullscreen usage is far and few between. As far as I can recall, some emulators don't even do dedicated fullscreen, do they? Would that be a concern given the spotty performance as you mention that can change on a dime?
jorimt wrote:
30 Jun 2020, 22:18
lc155 wrote:
30 Jun 2020, 21:39
And now, for the more esoteric usage: Emulators. From what I've read, the majority of emulators do not readily support VRR out of the box (Retroarch seems to do at least), so VRR would have to be forced, I'm presuming? Let's take a specific example: Dolphin.
It's pretty easy to get it working in the likes of RetroArch, for instance, and as for Dolphin, last time I checked, I don't think there was anything particular you had to do to get VRR working.
Okay, great. Thanks. I hope this applies as well to older emulators too.
jorimt wrote:
30 Jun 2020, 22:18
lc155 wrote:
30 Jun 2020, 21:39
Some games run at 30fps, some at 60fps. Some even at 50fps for select PAL titles. For the 30fps games, with my above understanding of LFC, then VRR should be activated while playing those titles, correct?
Yes.
Perfect.
jorimt wrote:
30 Jun 2020, 22:18
lc155 wrote:
30 Jun 2020, 21:39
And if so, do I still need to configure my monitor refresh rate to frame double (so 120Hz on 60Hz output from the emulator, or 100/150Hz from 50Hz output) every time I want to emulate a game, since 144Hz doesn't divide cleanly? It all gets a bit confusing. Having to change refresh rate every time would get a bit tiresome as well. I'd do it if there was no other option, but just wondering.

For the games which run with very esoteric frame rates of something like 59.7fps, I remember reading something about how G-Sync was a very useful tool in managing to smooth the juddering from those games out, due to the monitor being able to match those uneven frames. Is this something Freesync is able to do as well? I only read it in the context of G-Sync, so just wanted to be sure. I am unsure if the issue with these games was the uneven frame rates or the inconsistent frame times.
G-SYNC will take care of this automatically. That's what it's made for; matching the refresh rate to the framerate. "Clean" division isn't required, as it can adjust the refresh rate at the decimal level during variable or fixed FPS within the refresh rate.

That said, G-SYNC only fixes V-SYNC-induced stutter, it can't fix system-side stutter, so if the given game has innately poor frame pacing, G-SYNC won't mask or smooth it over, but will instead show it accurately, as it can only reflect what the system is outputting.
Fair enough. I recall a video on YouTube saying why G-Sync matters for emulation, and it specifically talked about older games with esoteric frame rates. I presume you're aware of it? I guess they were referencing how G-Sync would be able to match the monitor response to said esoteric frame rates whereas in the past it was stuck on 50/60Hz TVs and would judder in panning motion?

As for the clean division, I recall Blur Buster mentioning that frame doubling or tripling can reduce lag even if the original content is only outputting at say, 60 frames, while the monitor is set to 120 due to something to do with frame updates. Would this still not apply even when using G-sync? Then again, if VRR is in effect, the monitor would be outputting what the emulator is, and the monitor response time setting wouldn't apply? I'm not sure how this would work, to be honest.

(Also man, it kind of confusing trying to refer to G-Sync as G-Sync Compatible and not thinking of the specific module).

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Re: Some Freesync Questions

Post by Chief Blur Buster » 01 Jul 2020, 11:32

lc155 wrote:
01 Jul 2020, 10:38
As for the clean division, I recall Blur Buster mentioning that frame doubling or tripling can reduce lag even if the original content is only outputting at say, 60 frames, while the monitor is set to 120 due to something to do with frame updates.
It's not the frame doubling or frame tripling. It's the accelerated delivery of the first frame.

Basically, on a 120Hz monitor, they typically display refresh cycles in 1/120sec. So 60fps frames are displayed in 1/120sec. The fact that the frame is repeated is simply essentially a NOP (do-nothing-operation), just stuffing/padding/filling until the next changed frame.

Re-refreshing a refresh is like replacing an image with an identical image: It does nothing on a typical sample-and-hold LCD.

It's the first refresh cycle containing the changed frame that matter. If that refresh cycle is displayed faster, then you get less lag.

That's why 60fps at 120Hz is less laggy than 60fps at 60Hz, in the ideal situation.
lc155 wrote:
01 Jul 2020, 10:38
Would this still not apply even when using G-sync?
It's unnecessary. That "first" refresh cycle is displayed at the full velocity of max-Hz.

For example, if you have a 120Hz G-SYNC monitor, all frame rates have frames that display in 1/120sec, and that frame persists on the screen. You don't need to re-refresh or re-display.

Does this explanation help better?

More Information:

To understand even better, look at High Speed Videos of an Screen Refreshing. Not all pixels refresh at the same time. On a 60Hz, the screen refreshes in a 1/60sec scanout (the sweep effect, the wipe effect that goes from top-to-bottom). On a 120Hz, the screen refreshes in a 1/120sec scanout (first pixel change to last pixel change).

On a variable refresh rate monitor, the scanout velocity is constant (max speed), but the interval between scanout will vary (sync to framerate). On a fixed-Hz monitors, the scanout can only be scheduled at fixed Hz intervals, so framedrops are pushed to the next refresh sweep (i.e. 1/60sec later). While VRR monitors don't have such a restriction, the refresh scanout sweeps occur at frametime apart.
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jorimt
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Re: Some Freesync Questions

Post by jorimt » 01 Jul 2020, 14:16

lc155 wrote:
01 Jul 2020, 10:38
I see. I'm used to using borderless fullscreen due to my habit of tabbing out of games quite often. Dedicated fullscreen usage is far and few between. As far as I can recall, some emulators don't even do dedicated fullscreen, do they? Would that be a concern given the spotty performance as you mention that can change on a dime?
Have you tried exclusive fullscreen in the latest versions of Windows 10? Because it now defaults to a hybrid borderless/exclusive mode that allows faster and more seamless alt + tabbing.

As for emulator support of exclusive fullscreen, RetroArch does, as does Dolphin (the two I primarily use), don't know about the others off the top of my head though.

Borderless G-SYNC mode, in my personal experience, isn't too bad (I have to use it for key games that don't support exclusive), there's just a possibility frametime performance might suffer slightly when compared to exclusive, but this isn't always the case.
lc155 wrote:
30 Jun 2020, 21:39
I recall a video on YouTube saying why G-Sync matters for emulation, and it specifically talked about older games with esoteric frame rates. I presume you're aware of it? I guess they were referencing how G-Sync would be able to match the monitor response to said esoteric frame rates whereas in the past it was stuck on 50/60Hz TVs and would judder in panning motion?
Not sure I've seen the video in question (have a link?), but for all I know, they got that from my article:
https://blurbusters.com/gsync/gsync101- ... ttings/13/

But, yes, that's the case.
lc155 wrote:
30 Jun 2020, 21:39
(Also man, it kind of confusing trying to refer to G-Sync as G-Sync Compatible and not thinking of the specific module).
- G-SYNC = G-SYNC display containing hardware module
- G-SYNC Ultimate = G-SYNC display containing hardware module + HDR support
- G-SYNC Compatible = FreeSync display (either officially or unofficially) supporting software variant of G-SYNC via Nvidia drivers
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Re: Some Freesync Questions

Post by lc155 » 01 Jul 2020, 15:59

Thanks for the great and knowledgable responses, guys!
Chief Blur Buster wrote:
01 Jul 2020, 11:32
lc155 wrote:
01 Jul 2020, 10:38
As for the clean division, I recall Blur Buster mentioning that frame doubling or tripling can reduce lag even if the original content is only outputting at say, 60 frames, while the monitor is set to 120 due to something to do with frame updates.
It's not the frame doubling or frame tripling. It's the accelerated delivery of the first frame.

Basically, on a 120Hz monitor, they typically display refresh cycles in 1/120sec. So 60fps frames are displayed in 1/120sec. The fact that the frame is repeated is simply essentially a NOP (do-nothing-operation), just stuffing/padding/filling until the next changed frame.

Re-refreshing a refresh is like replacing an image with an identical image: It does nothing on a typical sample-and-hold LCD.

It's the first refresh cycle containing the changed frame that matter. If that refresh cycle is displayed faster, then you get less lag.

That's why 60fps at 120Hz is less laggy than 60fps at 60Hz, in the ideal situation.
I think I understand.
Chief Blur Buster wrote:
01 Jul 2020, 11:32
lc155 wrote:
01 Jul 2020, 10:38
Would this still not apply even when using G-sync?
It's unnecessary. That "first" refresh cycle is displayed at the full velocity of max-Hz.

For example, if you have a 120Hz G-SYNC monitor, all frame rates have frames that display in 1/120sec, and that frame persists on the screen. You don't need to re-refresh or re-display.

Does this explanation help better?

More Information:

To understand even better, look at High Speed Videos of an Screen Refreshing. Not all pixels refresh at the same time. On a 60Hz, the screen refreshes in a 1/60sec scanout (the sweep effect, the wipe effect that goes from top-to-bottom). On a 120Hz, the screen refreshes in a 1/120sec scanout (first pixel change to last pixel change).

On a variable refresh rate monitor, the scanout velocity is constant (max speed), but the interval between scanout will vary (sync to framerate). On a fixed-Hz monitors, the scanout can only be scheduled at fixed Hz intervals, so framedrops are pushed to the next refresh sweep (i.e. 1/60sec later). While VRR monitors don't have such a restriction, the refresh scanout sweeps occur at frametime apart.
So in practical terms, to see if I understand this correctly, given my first example:

With a 144Hz G-SYNC Compatible 38GN950, I can safely leave the monitor at 144Hz (or 160Hz with the supported OC) and, while running Dolphin, LFC will ensure G-SYNC is always activated even if the game is running at 30fps instead of 50/60. G-SYNC will also ensure that the frames are updating at the maximum possible speed instead of waiting for fixed Hz intervals, meaning that lag will be as minimal as it can possibly be, and you won't suffer from juddering in motion caused by non-integer division (such as a 24fps film running on a 60Hz monitor where it doesn't cleanly divide). As G-SYNC is taing care of all of this, changing the monitor refresh rate to be an integer division of the game (such as 120Hz for a 60Hz game) is therefore redundant and unnecessary.

Does that sound right?

I also read (I think from you) somewhere that while the implementation of LFC (and the G-SYNC module version of it I think) can have issues with stuttering at low frames, this has more to do with uneven frame pacing/timing (aka framerate is jumping all over the place and isn't stable). In short, a 30fps emulated game that is running stable should be a perfect application for smooth LFC?
jorimt wrote:
01 Jul 2020, 14:16
lc155 wrote:
01 Jul 2020, 10:38
I see. I'm used to using borderless fullscreen due to my habit of tabbing out of games quite often. Dedicated fullscreen usage is far and few between. As far as I can recall, some emulators don't even do dedicated full screen, do they? Would that be a concern given the spotty performance as you mention that can change on a dime?
Have you tried exclusive fullscreen in the latest versions of Windows 10? Because it now defaults to a hybrid borderless/exclusive mode that allows faster and more seamless alt + tabbing.

As for emulator support of exclusive fullscreen, RetroArch does, as does Dolphin (the two I primarily use), don't know about the others off the top of my head though.

Borderless G-SYNC mode, in my personal experience, isn't too bad (I have to use it for key games that don't support exclusive), there's just a possibility frametime performance might suffer slightly when compared to exclusive, but this isn't always the case.
I have not, so I was unaware of this. That sounds pretty good if that is now the case!

Thanks for the info about those two emulators. It is probably the older ones (like the GBA and SNES, etc.) emulators that would lack dedicated support for this, I imagine.

Noted, thanks.
jorimt wrote:
01 Jul 2020, 14:16
lc155 wrote:
30 Jun 2020, 21:39
I recall a video on YouTube saying why G-Sync matters for emulation, and it specifically talked about older games with esoteric frame rates. I presume you're aware of it? I guess they were referencing how G-Sync would be able to match the monitor response to said esoteric frame rates whereas in the past it was stuck on 50/60Hz TVs and would judder in panning motion?
Not sure I've seen the video in question (have a link?), but for all I know, they got that from my article:
https://blurbusters.com/gsync/gsync101- ... ttings/13/

But, yes, that's the case.
I believe this was the video in question. He talks about how certain arcade games run at really esoteric framerates which result in juddering on standard displays, whereas VRR can kick in here and correct for that (as forcing old games to run at higher frame rates just results in them speeding up). It's a fairly old video now but I imagine the point remains the same.

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Re: Some Freesync Questions

Post by jorimt » 01 Jul 2020, 16:22

lc155 wrote:
01 Jul 2020, 15:59
Thanks for the info about those two emulators. It is probably the older ones (like the GBA and SNES, etc.) emulators that would lack dedicated support for this, I imagine.
Not sure if you're aware, but RetroArch is simply an aggregate interface for some of the more popular emulators. You should take a look; you may find it already supports usage of some of your existing standalone versions.
lc155 wrote:
30 Jun 2020, 21:39
I believe this was the video in question. He talks about how certain arcade games run at really esoteric framerates which result in juddering on standard displays, whereas VRR can kick in here and correct for that (as forcing old games to run at higher frame rates just results in them speeding up). It's a fairly old video now but I imagine the point remains the same.
Ah, that definitely pre-dates my article then. Yes, if your VRR monitor is above 60Hz, and the emulated title has a certain internal FPS limit, G-SYNC will match it exactly, and, unlike standalone V-SYNC, it will do it without additional input lag or stutter.
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Re: Some Freesync Questions

Post by lc155 » 01 Jul 2020, 17:16

jorimt wrote:
01 Jul 2020, 16:22
lc155 wrote:
01 Jul 2020, 15:59
Thanks for the info about those two emulators. It is probably the older ones (like the GBA and SNES, etc.) emulators that would lack dedicated support for this, I imagine.
Not sure if you're aware, but RetroArch is simply an aggregate interface for some of the more popular emulators. You should take a look; you may find it already supports usage of some of your existing standalone versions.
I was vaguely aware, but have no personal experience with it as I'm just used to just having all my emulators separated, perhaps I'll give it a try. I just remembered hearing about RetroArch specific issues and figured it was perhaps more involved than a simple aggregate interface. Do they develop some bundled emulators further or something? I'll admit I have been out of the scene for a number of years and was interested in coming back to it recently.
jorimt wrote:
01 Jul 2020, 16:22
lc155 wrote:
30 Jun 2020, 21:39
I believe this was the video in question. He talks about how certain arcade games run at really esoteric framerates which result in juddering on standard displays, whereas VRR can kick in here and correct for that (as forcing old games to run at higher frame rates just results in them speeding up). It's a fairly old video now but I imagine the point remains the same.
Ah, that definitely pre-dates my article then. Yes, if your VRR monitor is above 60Hz, and the emulated title has a certain internal FPS limit, G-SYNC will match it exactly, and, unlike standalone V-SYNC, it will do it without additional input lag or stutter.
Just to clarify, what do you mean specifically by 'if your VRR monitor is above 60Hz'. Is there something special about that, or did you mean 'If the monitor is at or above 60Hz'? Since in the linked video, juddering was an issue with 60Hz when the game ran at 59.1 or 54 or whatever that didn't integer divide. Just making sure I understand properly. I never knew how complex monitor refresh tech really was until I started looking into this stuff.

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Re: Some Freesync Questions

Post by jorimt » 01 Jul 2020, 17:34

lc155 wrote:
01 Jul 2020, 17:16
I was vaguely aware, but have no personal experience with it as I'm just used to just having all my emulators separated, perhaps I'll give it a try. I just remembered hearing about RetroArch specific issues and figured it was perhaps more involved than a simple aggregate interface. Do they develop some bundled emulators further or something? I'll admit I have been out of the scene for a number of years and was interested in coming back to it recently.
Retroarch is a "front end" for emulators. You load the emulators as "cores," and they then, for the most part, behave as they do when standalone. You just manage them differently:
https://www.retroarch.com/
lc155 wrote:
30 Jun 2020, 21:39
Just to clarify, what do you mean specifically by 'if your VRR monitor is above 60Hz'. Is there something special about that, or did you mean 'If the monitor is at or above 60Hz'? Since in the linked video, juddering was an issue with 60Hz when the game ran at 59.1 or 54 or whatever that didn't integer divide. Just making sure I understand properly. I never knew how complex monitor refresh tech really was until I started looking into this stuff.
VRR needs a few frames of breathing room below the max refresh rate (-3 FPS is typically safe) to stay within range, else it reverts to fixed refresh rate behavior. This is mainly due to the fact that 100% perfect frametime is not achievable with FPS limiters (or modern systems).

So if you have a 60.1 FPS emulated title, for instance, and only have a 60Hz G-SYNC monitor, VRR will disengage. However, if you have, say, a 144Hz monitor, you'll have plenty of overhead for the game to run at 60.1hz and remain in the VRR range.

Emulated games that run at 54 FPS however, would be well enough within the refresh rate to use a 60Hz VRR monitor, for instance.
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Re: Some Freesync Questions

Post by Chief Blur Buster » 01 Jul 2020, 17:51

If you use RTSS or a well framepaced 8bit emulator, one only needs about 60.5Hz for VRR to engage at 60fps.

Emulators and RTSS have consistent framepacing. RTSS is precise enough and the refresh rate slow enough (half Hz = 8ms) that a 0.5fps cap-below helps emulators a LOT. Also GPU use closer to 50% instead of 100% while in Performance Mode, often helps more accurate cap-based framepacing. Most emulators don’t drive a GPU into the ground, so tighter capping is more practical. The frametime jitter will be small enough that 0.5Hz-below is enough breathing room for the emulator use-case.

3fps-below is just well-tested boilerplate VRR advice that is good, but the reality is sometimes 0.2fps-to-0.5fps below is OK for emulator use. Also, 5-to-8fps-below is probably sometimes needed for 280Hz-360Hz, due to ultrashort refreshtimes.

The good news:
Overclock your 4K 60Hz “40-60Hz” generic FreeSync monitor to 60.5Hz, to enable low-lag VRR-operated 60Hz, while enjoying MAME HLSL CRT effects enhanced by the 4K resolution. Even 60fps at 60.25Hz VRR actually helps emulator latency, depending on emulator, GPU load, Performance Mode (zero power management jitter), etc.
Head of Blur Busters - BlurBusters.com | TestUFO.com | Follow @BlurBusters on Twitter

       To support Blur Busters:
       • Official List of Best Gaming Monitors
       • List of G-SYNC Monitors
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       • List of Ultrawide Monitors

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