How To Decrease Input Latency When Running at Non-Native Resolution?

[bmichaels556]

Hey folks,

 

I'm on an MSI 1080p 144hz monitor. "Optix" line, but forget model number. Have been quite happy with it!

 

I'm almost always playing at 1080p for higher framerates, but often times, especially for older games, I like to play at 1440p or even 4K. Especially for just messing around and extra supersampling detail, or even recording etc.

 

One thing I've noticed is that when running non-native, especially at 4K (but also at 1440p), I'm getting a LOT of extra input latency. One issue was that I had vsync (maybe was fast sync?) on in Nvidia control panel, so I turned that off and that helped. I think what happened was... When I'm running monitor at 144hz, it was letting framerate run mostly free, but when I would change to 1440p or 4K, it was limiting monitor to 60fps, which sort of forced vsync to work, which was adding latency if that makes sense? I also made custom resolutions in Nvidia control panel for 1440p120 and 4K120 to make sure it wasn't limiting framerates and monitor seems to be fine with it. Everyone knows the deal with vsync adding latency, no big deal, so these steps seemed to help.

 

But there's still extra latency. Greater than with say running 1080p at a locked 60fps, so it's more than just the input latency of a lower framerate. Like, 1080p60 still feels relatively smooth. Not buttery like running higher at even 90fps, but DOES feel RESPONSIVE, just not as visually smooth if that makes sense. Not the case with 1440p, but even worse at 4K. I assume it's from the monitor first having to convert the image down to 1080p and then display it, adding whatever amount of latency.

 

Is there any way to fix or at least alleviate this more than I've already been able to? Letting framerate run free and THEN using MSI Afterburner / Rivatuner to 60fps to cut down on any choppiness etc (or just run at 120 fps if it's a much older game for double 60 for recording..?), but there's still the extra latency. I've also tried Nvidia image sharpening or whatever it's called, and honestly... It didn't look good to me, and I didn't even fully understand it. I dunno, it was weird.

 

Any ideas? Thanks so much for your help!  

[Vishera]

32 minutes ago, bmichaels556 said:

One thing I've noticed is that when running non-native, especially at 4K (but also at 1440p), I'm getting a LOT of extra input latency. One issue was that I had vsync (maybe was fast sync?) on in Nvidia control panel, so I turned that off and that helped.

Framerate is a major factor when it comes to input latency,

The higher the framerate the lower the input latency from input devices (though in addition to that input devices have their own input latency)

Therefore by limiting the frame rate or using higher resolutions or anything that will lower the framerate the input latency will increase.

[porina]

To clarify, the monitor is native 1080p but you can send higher resolutions to it and it will resize for you? The alternative is to do the scaling on GPU side and output 1080p to display. Use DSR or DLDSR on nvidia GPUs, I think AMD equivalent is VSR.

 

54 minutes ago, bmichaels556 said:

I've also tried Nvidia image sharpening or whatever it's called, and honestly... It didn't look good to me, and I didn't even fully understand it. I dunno, it was weird.

NIS is upscaling, rendering at lower resolution and resize to bigger. Wrong way around for you. (DL)DSR renders at high resolution and resizes it down, which sounds like what you're trying to do.

[bmichaels556]

On 2/3/2023 at 7:49 AM, Vishera said:

Framerate is a major factor when it comes to input latency,

The higher the framerate the lower the input latency from input devices (though in addition to that input devices have their own input latency)

Therefore by limiting the frame rate or using higher resolutions or anything that will lower the framerate the input latency will increase.

The latency is higher than the input latency difference of using 60fps vs a higher frame/refresh rate.

[bmichaels556]

On 2/3/2023 at 8:05 AM, porina said:

To clarify, the monitor is native 1080p but you can send higher resolutions to it and it will resize for you? The alternative is to do the scaling on GPU side and output 1080p to display. Use DSR or DLDSR on nvidia GPUs, I think AMD equivalent is VSR.

 

NIS is upscaling, rendering at lower resolution and resize to bigger. Wrong way around for you. (DL)DSR renders at high resolution and resizes it down, which sounds like what you're trying to do.

I think I confused the names. Yeah, I used DSR and didn't fully understand it, and honestly, it didn't seem to look very good, at least in my limited testing. It's also not 100% clear to me how I know if I'm using "4K Regular", vs 4K DSR and downscaling to 1080p. Also if I'm recording, would Nvidia GeForce Experience be recording the native 4K before it's scaled, or would it be recording the 1080p downscaled that I'm getting on my monitor? I would think it's the former, but not entirely sure. Will look deeper into this though.

 

Maybe I'll just delete any custom resolutions for 4K and see how that goes, which is how I remember trying it and it not looking good. Maybe I gotta' play with the smoothing %. 

[Vishera]

1 hour ago, bmichaels556 said:

The latency is higher than the input latency difference of using 60fps vs a higher frame/refresh rate.

Refresh rate only affects latency from the display, framerate also affects latency from input devices such as keyboard, mouse, controllers, etc.

[bmichaels556]

6 minutes ago, Vishera said:

Refresh rate only affects latency from the display, framerate also affects latency from input devices such as keyboard, mouse, controllers, etc.

Right, so... Okay, so maybe there's extra latency in one of those steps by changing resolution? Which is why I'm pointing to it probably being the display having to scale and process things, whereas the input latency is fine. Well... I will say that in games where I can do it, borderless windowed mode where I simply go up to 4K that way, doesn't seem to have the same increased latency, as say, dedicated fullscreen 4K at equivalent framerate and/or refresh rate. Like, assuming I'm always limiting to 60, it's still higher in 4K dedicated fullscreen, but not higher (noticeably) in 4K borderless windowed. I suspect the latter is being scaled via GPU, and the former by display or both, adding latency..?

[Vishera]

4 minutes ago, bmichaels556 said:

Right, so... Okay, so maybe there's extra latency in one of those steps by changing resolution? Which is why I'm pointing to it probably being the display having to scale and process things, whereas the input latency is fine. Well... I will say that in games where I can do it, borderless windowed mode where I simply go up to 4K that way, doesn't seem to have the same increased latency, as say, dedicated fullscreen 4K at equivalent framerate and/or refresh rate. Like, assuming I'm always limiting to 60, it's still higher in 4K dedicated fullscreen, but not higher (noticeably) in 4K borderless windowed. I suspect the latter is being scaled via GPU, and the former by display or both, adding latency..?

Try using DSR instead of custom resolutions, you will still be able to run the desktop and games in 4K.