High refresh rate monitors at 60hz?

[2mg]

Why is is that high refresh rate monitors have more input lag at 60hz?

I understand that 60fps causes more input lag, but online reviews always note that most high refresh rate monitors have additional input lag at 60hz, why is that?

To add VRR into the mix - if the FPS falls to 60fps, causing the panel to drop via VRR to 60hz (with some frame doubling), does that means that effectively the monitor is in 60hz and also has that additional lag?

[RealNC]

Why is is that high refresh rate monitors have more input lag at 60hz?

Probably because the 60Hz mode is an afterthought that they didn't care about.

To add VRR into the mix - if the FPS falls to 60fps, causing the panel to drop via VRR to 60hz (with some frame doubling), does that means that effectively the monitor is in 60hz and also has that additional lag?

Nope. Only the 60Hz fixed refresh mode has this issue. With VRR, the monitor always uses a fixed scanout speed, regardless of current VRR refresh rate. If you run 240Hz for example with VRR on, the scanout speed is still that of 240Hz even if VRR Hz is 60.

[2mg]

Nope. Only the 60Hz fixed refresh mode has this issue. With VRR, the monitor always uses a fixed scanout speed, regardless of current VRR refresh rate. If you run 240Hz for example with VRR on, the scanout speed is still that of 240Hz even if VRR Hz is 60.

So blur in that case is due to low FPS (sample and hold) only?

[RealNC]

So blur in that case is due to low FPS (sample and hold) only?

Yes. And of course the response time of the panel as well. 60FPS on a VA panel is gonna have a bit more motion blur than 60FPS on an OLED.

[Espionage724]

Why is is that high refresh rate monitors have more input lag at 60hz?

Probably because the 60Hz mode is an afterthought that they didn't care about.

What's that mean technically?

Is it higher because of a lack-of EDID timings? What if I hand-generate it based on panel and chip specs?

[kyube]

What's that mean technically?
Is it higher because of a lack-of EDID timings? What if I hand-generate it based on panel and chip specs?

Yes, you can make a custom EDID (“custom resolution”) which is of a lower refresh rate, but with the panel's native pixel clock.
You're essentially mimicking VRR behavior, but in using a fixed refresh rate.
No reviewer online does high precision input lag testing to confirm whether this helps, however.

From slow-mo camera footage, the scanout difference is very apparent.

Though, the practicality of such endeavours is questionable, as VRR exists & is much less of a hassle...

Yes. And of course the response time of the panel as well. 60FPS on a VA panel is gonna have a bit more motion blur than 60FPS on an OLED.

I haven't seen a modern LCD panel not have fast enough G2G RT values for a 16,67ms window for more than a decade now.
60Hz should be similar, if not equivalent, in terms of visual experience when dynamic content is displayed on LCD & OLED nowadays.

Why is is that high refresh rate monitors have more input lag at 60hz?

I understand that 60fps causes more input lag, but online reviews always note that most high refresh rate monitors have additional input lag at 60hz, why is that?

To add VRR into the mix - if the FPS falls to 60fps, causing the panel to drop via VRR to 60hz (with some frame doubling), does that means that effectively the monitor is in 60hz and also has that additional lag?

See my first reply above. Don't rely on all input lag testing data you see online.

[RealNC]

Yes. And of course the response time of the panel as well. 60FPS on a VA panel is gonna have a bit more motion blur than 60FPS on an OLED.

I haven't seen a modern LCD panel not have fast enough G2G RT values for a 16,67ms window for more than a decade now.
60Hz should be similar, if not equivalent, in terms of visual experience when dynamic content is displayed on LCD & OLED nowadays.

The higher the response time, the more ghosting. VA's suffer from this a lot. Refresh rate doesn't matter.

[kyube]

The higher the response time, the more ghosting. VA's suffer from this a lot. Refresh rate doesn't matter.

Yes. “Ghosting” / “black smearing” are community-thrown terms to describe slower-than-refresh rate G2G RT's, particularly in the darker gray shades.
My claim is that “VA's suffer from this a lot” is based on a small sample size of old VA implementations.
Newer +120Hz VA panels (e.g. INNOCN 27G1S or MSI's M30V) have been improved compared to their predecessors and fit the darker gray transitions easily within the 16,67ms window, which would make 60Hz look similar if not equivalent to other LCD subtypes or OLED.

[RealNC]

Yes. “Ghosting” / “black smearing” are community-thrown terms to describe slower-than-refresh rate G2G RT's, particularly in the darker gray shades.
My claim is that “VA's suffer from this a lot” is based on a small sample size of old VA implementations.
Newer +120Hz VA panels (e.g. INNOCN 27G1S or MSI's M30V) have been improved compared to their predecessors and fit the darker gray transitions easily within the 16,67ms window, which would make 60Hz look similar if not equivalent to other LCD subtypes or OLED.

That's not how that works. You cannot hide the transition. The previous state of each pixel is going to be visible for a while, no matter what. You could have a 30Hz mode and it would still be visible.

[kyube]

That's not how that works. You cannot hide the transition. The previous state of each pixel is going to be visible for a while, no matter what. You could have a 30Hz mode and it would still be visible.

I don't really meant hiding it.
My interpretation is:
If the VA in question has a theoretical G2G RT heatmap, where the RT's are distributed in a uniform way (where RT<refresh rate, regardless of the combination within the 0-255 range)
it will look similar, if not identical, in TestUFO motion pursuit photographs as OLEDs (which are RT<<refresh rate)

This assumes that OD is well-tuned, for the LCD counterpart.

This could be a misunderstanding on my part in regards to the behavior of sample & hold displays, feel free to correct me!

Note: For the sake of my arguement, assume that each transition of the LCD is <4,16777ms (e.g. 3ms at all times, regardless of transition chosen or the precision range of the heatmap)

e.g.:
27G1S (240Hz VA LCD)


OLED (240Hz QD)