Some questions regarding Adaptive Sync/Variable Refresh Rate

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.
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Aldagar
Posts: 18
Joined: 12 Mar 2020, 14:27

Some questions regarding Adaptive Sync/Variable Refresh Rate

Post by Aldagar » 12 Mar 2020, 15:37

First of all, let me say that I've been lurking this website for quite some time and I think it's a great source of reliable and useful information. Getting to the point, I'm in the market for a 1440p IPS monitor and I think I'll be settling for the ASUS PB278QV, which has a quite narrow Freesync range of 48-75 Hz, but I don't need high refresh rates and its price is adequate. I mostly play single player games (which I usually cap at 75-90 fps with RTSS or Radeon Chill on my current 60 Hz monitor) and emulators (capped at 30 or 60 fps).

I have never used a Freesync or G-Sync monitor, I understand its purpose is to prevent tearing and stuttering, but I've been researching about it and I've seen some complaints, notably:
  • Flickering/shimmering, most likely caused by brightness variations produced by inconsistent refresh rate and Low Framerate Compensation.
  • Ghosting/overshoot, most likely caused by the response time not adjusting accordingly to the refresh rate.
  • Input lag and a less snappy feel.
So my questions are the following:
  1. Can Freesync negatively affect the gaming experience?
  2. Does it degrade image quality, outputting an inconsistent and innacurate reproduction?
  3. Is Freesync worth it at a range of 48-75 Hz? Would it give a smoother experience if I play at a fixed framerate of 60 fps?
  4. Is the input lag noticeable or something to worry about?
Thanks in advance.

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Chief Blur Buster
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Re: Some questions regarding Adaptive Sync/Variable Refresh Rate

Post by Chief Blur Buster » 12 Mar 2020, 15:45

Aldagar wrote:
12 Mar 2020, 15:37
I'm in the market for a 1440p IPS monitor and I think I'll be settling for the ASUS PB278QV, which has a quite narrow Freesync range of 48-75 Hz, but I don't need high refresh rates and its price is adequate.
That's a bit narrow, you really want a wider FreeSync range if you want to use it in more games. It's almost only one-tenth as useful as a FreeSync range of 48Hz-144Hz, because with that wide a range, it can destutter motion below 48Hz through LFC.

LFC requires max-Hz that's more than 2x the min-Hz.

The good news is that FreeSync is typically a free feature of many new monitors, and FreeSync can be turned on/off.
Aldagar wrote:
12 Mar 2020, 15:37
and emulators (capped at 30 or 60 fps).
FreeSync actually reduces input lag for emulators, so enabling FreeSync for emulators should be beneficial.
Aldagar wrote:
12 Mar 2020, 15:37
I have never used a Freesync or G-Sync monitor, I understand its purpose is to prevent tearing and stuttering, but I've been researching about it and I've seen some complaints, notably:
  • Flickering/shimmering, most likely caused by brightness variations produced by inconsistent refresh rate and Low Framerate Compensation.
That is a known issue with some models -- it does not affect all of them. And besides, FreeSync can be turned off if this affects you. People want to keep it turned on because the advantages have often outweighed the disadvantages.
Aldagar wrote:
12 Mar 2020, 15:37
[*]Ghosting/overshoot, most likely caused by the response time not adjusting accordingly to the refresh rate.
That is a known issue with some models. The G-SYNC premium (and probably the FreeSync Premium Pro) pays for improved overdrive that makes it much better and more seamless.
Aldagar wrote:
12 Mar 2020, 15:37
[*]Input lag and a less snappy feel.
This is usually from professional competitive players, including esports players that earn thousands of dollars in a gaming career using uncapped frame rates and VSYNC OFF at frame rates well beyond refresh rate. However, VRR can be used competitively if you use it with the right games in the right situations. For example, G-SYNC rarely improves CS:GO scores, but can improve PUBG scores, though preferably at 240Hz, especially this allows your framerate fluctuation range is INSIDE the variable refresh rate range (TL;DR: Get a monitor with a humongous VRR range).

But it actually reduces input lag in your use case. FreeSync is lower lag than VSYNC ON, which makes FreeSync perfect for emulator use -- it improves emulator responsiveness. In other words "FreeSync is like a nearly-lagless VSYNC ON mode for the times where I hate VSYNC OFF". And guess what emulators use? Emulators don't use VSYNC OFF....

Besides, if it is ever a problem, just simply turn FreeSync OFF on your monitor. But FreeSync improves things 90% of the time, worsen things only 10% of the time. You can toggle it on/off as needed.

FreeSync looks like this www.testufo.com/freesync -- it is a good "single framedrop eraser" technology. If you love that idea, then get a wider VRR range.

For your use case, you're currently worrying about nothing. Go buy the monitor, though I'd be tempted to get something more expensive / better, especially if you like motion blur reduction for CRT-motion-clarity emulator use. A 120Hz monitor allows the 60Hz software-black-frame-insertion to halve motion blur, see www.testufo.com/blackframes ... But this might not be a priority of yours, given 90% of strobe backlights can significantly degrade color quality (unless it's a well chosen model)
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Aldagar
Posts: 18
Joined: 12 Mar 2020, 14:27

Re: Some questions regarding Adaptive Sync/Variable Refresh Rate

Post by Aldagar » 12 Mar 2020, 16:08

Chief Blur Buster wrote:
12 Mar 2020, 15:45
Aldagar wrote:
12 Mar 2020, 15:37
I'm in the market for a 1440p IPS monitor and I think I'll be settling for the ASUS PB278QV, which has a quite narrow Freesync range of 48-75 Hz, but I don't need high refresh rates and its price is adequate.
That's a bit narrow, you really want a wider FreeSync range if you want to use it in more games. It's almost only one-tenth as useful as a FreeSync range of 48Hz-144Hz, because with that wide a range, it can destutter motion below 48Hz through LFC.

LFC requires max-Hz that's more than 2x the min-Hz.

The good news is that FreeSync is typically a free feature of many new monitors, and FreeSync can be turned on/off.
Aldagar wrote:
12 Mar 2020, 15:37
and emulators (capped at 30 or 60 fps).
FreeSync actually reduces input lag for emulators, so enabling FreeSync for emulators should be beneficial.
Aldagar wrote:
12 Mar 2020, 15:37
I have never used a Freesync or G-Sync monitor, I understand its purpose is to prevent tearing and stuttering, but I've been researching about it and I've seen some complaints, notably:
  • Flickering/shimmering, most likely caused by brightness variations produced by inconsistent refresh rate and Low Framerate Compensation.
That is a known issue with some models -- it does not affect all of them. And besides, FreeSync can be turned off if this affects you. People want to keep it turned on because the advantages have often outweighed the disadvantages.
Aldagar wrote:
12 Mar 2020, 15:37
[*]Ghosting/overshoot, most likely caused by the response time not adjusting accordingly to the refresh rate.
That is a known issue with some models. The G-SYNC premium (and probably the FreeSync Premium Pro) pays for improved overdrive that makes it much better and more seamless.
Aldagar wrote:
12 Mar 2020, 15:37
[*]Input lag and a less snappy feel.
This is usually from professional competitive players, including esports players that earn thousands of dollars in a gaming career using uncapped frame rates and VSYNC OFF at frame rates well beyond refresh rate. However, VRR can be used competitively if you use it with the right games in the right situations. For example, G-SYNC rarely improves CS:GO scores, but can improve PUBG scores, though preferably at 240Hz, especially this allows your framerate fluctuation range is INSIDE the variable refresh rate range (TL;DR: Get a monitor with a humongous VRR range).

But it actually reduces input lag in your use case. FreeSync is lower lag than VSYNC ON, which makes FreeSync perfect for emulator use -- it improves emulator responsiveness. In other words "FreeSync is like a nearly-lagless VSYNC ON mode for the times where I hate VSYNC OFF". And guess what emulators use? Emulators don't use VSYNC OFF....

Besides, if it is ever a problem, just simply turn FreeSync OFF on your monitor. But FreeSync improves things 90% of the time, worsen things only 10% of the time. You can toggle it on/off as needed.

FreeSync looks like this www.testufo.com/freesync -- it is a good "single framedrop eraser" technology. If you love that idea, then get a wider VRR range.

For your use case, you're currently worrying about nothing. Go buy the monitor, though I'd be tempted to get something more expensive / better, especially if you like motion blur reduction for CRT-motion-clarity emulator use. A 120Hz monitor allows the 60Hz software-black-frame-insertion to halve motion blur, see www.testufo.com/blackframes ... But this might not be a priority of yours, given 90% of strobe backlights can significantly degrade color quality (unless it's a well chosen model)
I see. I'm actually not 100% determined to buy that specific model since it seems it's recent and there isn't any review out there, but you've cleared my doubts. Thank you.

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