Question about Asus VG279QM

[nanoBarre]

Based on reviews, this monitor has a high input lag at 60Hz. If I wanted to play graphically demanding games, where I would have 60-80 fps, but set to 280hz with VRR, would I also have high input lag?
Or high input lag is limiting hz to 60?

Sorry for my bad english

[jorimt]

Or high input lag is limiting hz to 60?

Correct, only at 60Hz; 280Hz VRR at ~60 FPS won't have it.

[PixelDuck87]

If VG279QM drops to 60hz then 40ms lag will be there. This is a very dodgy monitor with its 40ms input lag at 60z. No one measured what kinda input lag it has at 90hz/120hz/144hz etc... (or when does the high input lag anomaly stop? for example, Is it only at 60hz and not
at 61hz?).

I also asked same question on Rtings and the reply was "As the frame rate drops, the input lag increases. At 60Hz with VRR, we measured 40.4ms of input lag."

[RLCSContender*]

Not just the VG279QM but the MSI MAG251RX(but not as bad) and the Alienware A2720HF(but not as bad) suffers from this plague. This is easily detected by simply moving your mouse once you change the refresh rate to 60hz

Leaving freesync on will sort of mitigate this issue but that's an oxymoron. Any form of adaptive sync/variable refresh rate adds INPUT LAG anyway. The fast pixel transfers and movemenets for some monitors are simply not adept at lower refresh rates scanrates. if you want to play at 60hz, buy a 60hz monitor or a monitor that is close to that. Some 144hz monitors have low lag at 60hz, particularly the innolux panels.

The main problem are consoles at 60hz fixed refresh. The nintendo switch for example was a mortifying experience for me.

it got so bad, my Sanyo 720p HDTV that my parents bought me almost 20 years ago(yes folks, i'm in my early 30s)has lower input lag at 60hz. As a matter of fact, i had to boot out my VG279QM for a few hours to play smash bros ultimate because i didn't own another monitor at the time.

[speancer]

Or high input lag is limiting hz to 60?

Correct, only at 60Hz; 280Hz VRR at ~60 FPS won't have it.

PixelDuck87 is right, I guess? He asked a specific question and received this answer from RTINGS, so seems like even when using G-SYNC Compatible/FreeSync this monitor has extreme input lag issue, getting progressively worse the lower fps/refresh rate goes.

[jorimt]

PixelDuck87 is right, I guess? He asked a specific question and received this answer from RTINGS, so seems like even when using G-SYNC Compatible/FreeSync this monitor has extreme input lag issue, getting progressively worse the lower fps/refresh rate goes.

Their wording isn't clear enough to determine what they meant.

When they say "At 60Hz with VRR, we measured 40.4ms of input lag," do they mean the max physical refresh rate set to 60Hz w/VRR enabled with a 60 or higher framerate, or do they mean the max physical refresh rate set to 280Hz w/VRR enabled and the framerate hovering at ~60?

Because that's two entirely seperate scenarios.

Increased 60Hz lag on 240Hz+ monitors is usually caused by a fixed scanrate (see: viewtopic.php?f=5&t=3441&start=490#p51937), so it would indeed be odd if it was creating the same input lag increase in an 280Hz/60 FPS VRR scenario.

[speancer]

Their wording isn't clear enough to determine what they meant.

When they say "At 60Hz with VRR, we measured 40.4ms of input lag," do they mean the max physical refresh rate set to 60Hz in the NVCP w/G-SYNC enabled with a 60 or higher framerate, or do they mean the max physical refresh rate set to 280Hz in the NVCP w/G-SYNC enabled and the framerate hovering at ~60?

Because that's two entirely seperate scenarios.

Increased 60Hz lag on 240Hz+ monitors is usually caused by a fixed scanrate (see: viewtopic.php?f=5&t=3441&start=490#p51937), so it would indeed be odd if it was creating the same input lag increase in an 280Hz/60 FPS VRR scenario.

I have second thoughts about it, too, but the way the question is asked strongly suggest that their answer refers to maximum refresh rate (280 Hz) and 60 fps when VRR is enabled (thus 60 Hz), because PixelDuck87 specifically asked about it. They actually corrected him, as they measured even higher input lag with VRR at 60 Hz, saying that "as the frame rate drops, the input lag increases."

On the other hand, RTINGS summary says: "It also has exceptionally low input lag when gaming at 280Hz, but, unfortunately, the 60Hz input lag is extremely high, so it's not a great choice for console gamers." This would mean that it's all about only fixed 60 Hz refresh rate being problematic... but not necessarily.

I do agree it's not 100% clear, it just appears logical to me that they answered a specific question. You know more about this stuff. Is this possible for the input lag to work like that, when you have 280 Hz and VRR enabled, and the lower fps goes, the worse input lag gets, to such extremes as in this case?

[PixelDuck87]

Just posted another question on Rtings on whether they do 60hz VRR or 280hz VRR with 60fps limiter.

Also, I'm wondering, won't "low framerate compensation" prevent the monitor from going 60hz so that 280hz VRR is out of the question which means they would have to set the monitor to 60hz for their messurments?

[jorimt]

Is this possible for the input lag to work like that, when you have 280 Hz and VRR enabled, and the lower fps goes, the worse input lag gets, to such extremes as in this case?

Only frametime should increase with ~60 FPS (or any lower FPS) at 280Hz in VRR mode.

Contrary to common understanding, VRR doesn't actually "change" the refresh rate, at least, the actual scanout time of the panel. That remains fixed at the currently set max physical refresh rate. So if it's set to 60Hz, regardless of VRR "refresh" rate or framerate, each frame will be scanned in at 16.6ms. Similarly, for 280Hz VRR, each frame will be scanned in at 3.6ms.

What VRR does change is how many times the scanout cycle repeats in a second. So if you have 280Hz VRR at 60 FPS, there are 60 scanout cycles completed per second, but each is still completing at the 280Hz rate of 3.6ms, whereas if you have 60Hz VRR at 60 FPS, there are also 60 scanout cycles completed per second, but each scanout cycle is now completing in 16.6ms.

Again, 60Hz input lag increase on 240Hz+ panels is usually limited to the physical 60Hz refresh rate due to the scanout conversion, and doesn't apply to VRR, as 60 FPS VRR at 280Hz is still technically a physical refresh rate of 280Hz, so no conversion is required.

I guess it still could be possible on that particular model, but I personally wouldn't know of a technical reason why.

Also, I'm wondering, won't "low framerate compensation" prevent the monitor from going 60hz so that 280hz VRR is out of the question which means they would have to set the monitor to 60hz for their messurments?

That's my guess, but who knows. Again, they're not being clear enough in their explanation.

[PixelDuck87]

Only frametime should increase with ~60 FPS (or any lower FPS) at 280Hz in VRR mode.

Contrary to common understanding, VRR doesn't actually "change" the refresh rate, at least, the actual scanout time of the panel. That remains fixed at the currently set max physical refresh rate. So if it's set to 60Hz, regardless of VRR "refresh" rate or framerate, each frame will be scanned in at 16.6ms. Similarly, for 280Hz VRR, each frame will be scanned in at 3.6ms.

What VRR does change is how many times the scanout cycle repeats in a second. So if you have 280Hz VRR at 60 FPS, there are 60 scanout cycles completed per second, but each is still completing at the 280Hz rate of 3.6ms, whereas if you have 60Hz VRR at 60 FPS, there are also 60 scanout cycles completed per second, but each scanout cycle is now completing in 16.6ms.

Again, 60Hz input lag increase on 240Hz+ panels is usually limited to the physical 60Hz refresh rate due to the scanout conversion, and doesn't apply to VRR, as 60 FPS VRR at 280Hz is still technically a physical refresh rate of 280Hz, so no conversion is required.

I guess it still could be possible on that particular model, but I personally wouldn't know of a technical reason why.

I had no idea that's how freesync/gsync works, I always thought it would directly change the refresh rate of the monitor on the fly... Thank you for explaining this!