VG27aq reporting refresh 2X FR?

Talk about NVIDIA G-SYNC, a variable refresh rate (VRR) technology. G-SYNC eliminates stutters, tearing, and reduces input lag. List of G-SYNC Monitors.
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Mdsjohna
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VG27aq reporting refresh 2X FR?

Post by Mdsjohna » 31 Mar 2021, 10:59

I recently upgrade to the Asus VG27AQ. I did a fair bit of research beforehand, but now that I have it home and have looked even more I got concerned about the low performance of this monitor at lower FPS. I have a GTX 1060 and though one day I would like to upgrade with availability and inflated prices it’s not happening anytime soon. I’m not a huge PC gamer but would like to potentially do more as well as have support for consoles including the ps5 when its actually available. Playing around with the settings a I noticed that in WOW, Destiny 2 and Diablo 3 this monitor seems to report doubling the refresh rate at anything below 70 fps. Change the in game cap to 71 and then the monitor reports 71. I show this in the pictures. This seems to happen on all three games. Googling this there is talk about doubling refreshes at below the VRR range but this it well above the 48hz min of this monitor.

What’s going on here? Does this help with Ghosting? Thank you.

Any recommendations to a similar price point monitor that has better moderate frame rate performance? I haven’t really noticed any ghosting or anything but haven’t really been gaming with it too much yet. Mostly just using it as my “work from home” covid monitor. Thank you.

How bad would a 4k 27” monitor be rendered at 1080p or 1440p upscaled to 4k?

They FPS is green top right and bottom right is he. They match exactly but the gist is doubling below 70fps and as it above.
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Re: VG27aq reporting refresh 2X FR?

Post by RealNC » 31 Mar 2021, 11:58

Mdsjohna wrote:
31 Mar 2021, 10:59
this monitor seems to report doubling the refresh rate at anything below 70 fps. Change the in game cap to 71 and then the monitor reports 71. I show this in the pictures. This seems to happen on all three games. Googling this there is talk about doubling refreshes at below the VRR range but this it well above the 48hz min of this monitor.
That's normal. Just because the monitor can do 48Hz does not mean that the GPU driver will choose to make use of that. If the driver thinks it's better to start LFC at 70hz, then you'll see this behavior.
What’s going on here? Does this help with Ghosting? Thank you.
Maybe. The reason LFC can be engaged at higher Hz might have something to do with ghosting, but it could be something else as well (like avoiding brightness changes.)
Any recommendations to a similar price point monitor that has better moderate frame rate performance? I haven’t really noticed any ghosting or anything but haven’t really been gaming with it too much yet. Mostly just using it as my “work from home” covid monitor. Thank you.
If you're not having any issues with this monitor, why replace it?
How bad would a 4k 27” monitor be rendered at 1080p or 1440p upscaled to 4k?
It's gonna be a bit blurry, but you can counteract that with NVidia's GPU upscaling + sharpening. You can find that setting in the NVidia control panel's "3D Settings" section. You can test it right now. Tick the "GPU scaling" checkbox there, but leave sharpening "off", because it's not a good idea to enable sharpening globally; it would result in sharpening everything, even games at native resolution. Instead, find the game's profile in the 3d settings, and enable sharpening there. Move the sharpening slider to 38%, and leave the "ignore film grain" slider to its default setting (should be 17% IIRC.) Then start that specific game, and switch it to 1920x1080. That's what I do on my 1440p monitor to play games at 1080p while maintaining the same subjective sharpness as native 1440p.

You can also leave the "gpu scaling" checkbox disabled, if you think your monitor is doing a better job at upscaling, although in most cases this will result in GPU scaling anyway, since monitors usually don't have the required resolutions listed as supported at all refresh rates. You can check that in the monitor's OSD though. If you play a game at 1080p, but the monitor's OSD says the current mode is 1440p, then that means GPU scaling is being used.

This will be similar on a 4K display.

However, since you have a 1xxxx series geforce GPU, you can instead enable "integer scaling". When you use that (don't use sharpening in that case), then you get "pixel doubling". On your 1440p display, you would then need to use a resolution that is exactly 1/2, 1/3, 1/4, etc of the native resolution. For 1440p, the 1/2 resolution is 720p (1280x720). On a 4K display, the 1/2 resolution is 1080p (1920x1080).

Integer scaling is going to result in an image that looks almost the same what you would get on a display that had that native resolution. So on a 27" 1440p display, playing at 720p with integer scaling will look very similar to what a 720p 27" monitor would look like. Obviously this is going to be very pixelated. A 27" 720p monitor would naturally have very large pixels (meaning very low DPI.) Similarly, 1080p with integer scaling on a 4K 34" display is going to look very similar to a 1080p 34" display.

So try both methods (sharpening or integer scaling) and see which one you like better. For resolutions that can't be integer scaled you obviously need to use the sharpening method, unless you're OK with not getting a fullscreen image.
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Mdsjohna
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Re: VG27aq reporting refresh 2X FR?

Post by Mdsjohna » 31 Mar 2021, 12:49

Maybe. The reason LFC can be engaged at higher Hz might have something to do with ghosting, but it could be something else as well (like avoiding brightness changes.)
See that's my problem the saying goes something like "you don't know what you don't know." I wasn't really aware of LFC. Something to research. I thought maybe it was something built into the monitor to keep refresh rates higher as the lower FR response performance seems to be bad from the reviews I have read. Doubling frames might help with that? I was just guessing.
If you're not having any issues with this monitor, why replace it?
Because now is the time, I have a limited window to return it. The thing is I'm not going to have extensive time to test it out in that window. I don't have the PS5 yet, I could try it with the PS4 pro I guess. Also the fact is for quite a while yet I wont be upgrading my hardware and with what I have I wont have blazing high FPS, there are reviews that say unless you consistently have high FR this isn't the best monitor. Maybe I wont even see any ghosting or overshoot, I don't know but I don't want to be two months out and its not returnable to find that it was a bad choice.

It's gonna be a bit blurry, but you can counteract that with NVidia's GPU upscaling + sharpening. You can find that setting in the NVidia control panel's "3D Settings" section. You can test it right now. Tick the "GPU scaling" checkbox there, but leave sharpening "off", because it's not a good idea to enable sharpening globally; it would result in sharpening everything, even games at native resolution. Instead, find the game's profile in the 3d settings, and enable sharpening there. Move the sharpening slider to 38%, and leave the "ignore film grain" slider to its default setting (should be 17% IIRC.) Then start that specific game, and switch it to 1920x1080. That's what I do on my 1440p monitor to play games at 1080p while maintaining the same subjective sharpness as native 1440p.

You can also leave the "gpu scaling" checkbox disabled, if you think your monitor is doing a better job at upscaling, although in most cases this will result in GPU scaling anyway, since monitors usually don't have the required resolutions listed as supported at all refresh rates. You can check that in the monitor's OSD though. If you play a game at 1080p, but the monitor's OSD says the current mode is 1440p, then that means GPU scaling is being used.

This will be similar on a 4K display.

However, since you have a 1xxxx series geforce GPU, you can instead enable "integer scaling". When you use that (don't use sharpening in that case), then you get "pixel doubling". On your 1440p display, you would then need to use a resolution that is exactly 1/2, 1/3, 1/4, etc of the native resolution. For 1440p, the 1/2 resolution is 720p (1280x720). On a 4K display, the 1/2 resolution is 1080p (1920x1080).

Integer scaling is going to result in an image that looks almost the same what you would get on a display that had that native resolution. So on a 27" 1440p display, playing at 720p with integer scaling will look very similar to what a 720p 27" monitor would look like. Obviously this is going to be very pixelated. A 27" 720p monitor would naturally have very large pixels (meaning very low DPI.) Similarly, 1080p with integer scaling on a 4K 34" display is going to look very similar to a 1080p 34" display.

So try both methods (sharpening or integer scaling) and see which one you like better. For resolutions that can't be integer scaled you obviously need to use the sharpening method, unless you're OK with not getting a fullscreen image.
Im going to play around with this right away. As far as I can see though integer scaling is only available on the 1660 and up.

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Re: VG27aq reporting refresh 2X FR?

Post by RealNC » 31 Mar 2021, 13:29

Mdsjohna wrote:
31 Mar 2021, 12:49
Im going to play around with this right away. As far as I can see though integer scaling is only available on the 1660 and up.
Right. I forgot that Pascal GPUs don't integer scale.

Sharpening is a good solution though. I was doing that using ReShade way before nvidia added a sharpening shader in the control panel. Another thing to keep in mind is that if you enable the "GPU scaling" checkbox in the 3D settings "Image sharpening" option, you also get some extra resolutions added automatically. On a 1440p display, this adds an extra resolutions section called "Scaling Resolution" with resolutions for 0.85x, 0.75x, 0.66x and 0.50x scaling:

Image

So this is kind of the reverse of DSR. 1224p (0.85x) is interesting, as it's half-way between 1440p and 1080p. Sometimes that's enough to reach your FPS target in a particular game. 960p is also interesting if a game still struggles at 1080p and you don't want to drop all the way down to 720p.

The sharpening amount might need tweaking though. In my tests, on a Maxwell GPU (980 Ti) which does simple bilinear upscaling, I need somewhere between 0.36 and 0.40 when upscaling 1080p to counteract the bilinear filter's blur and reach the same subjective sharpness as 1440p. When upscaling 720p, I need something between 0.44 and 0.50 instead. So I suppose the lower the resolution you want to upscale is, the more sharpening it needs. I don't know however if Pascal GPUs also use bilinear GPU upscaling, or if they use something better. If it's not bilinear, then you probably need less sharpening.

Unfortunately, you cannot screenshot upscaled resolutions. If you try, all you get will be a sharpened 1080p screenshot, not the upscaled 1440p result. The way I tested this to find out my optimal sharpening amount was to first take a screenshot at native 1440p resolution (without sharpening of course), then:
  • Enable sharpening.
  • Switch the game to 1080p.
  • Make sure fullscreen optimizations are NOT disabled in the game's exe properties
  • Disable G-SYNC globally.
  • Use the same refresh rate in the game and the desktop.
This allows very fast alt+tabbing out and back into the game. I had an image viewer open in fullscreen mode, viewing the original native 1440p screenshot, and then quickly alt+tab between the game and the image viewer to compare how the sharpness compares between the two. With that method, I arrived at 0.36 to 0.40 sharpening amount for 1080p. Anything between those two values looks subjectively as sharp as native 1440p. ("Subjectively" meaning the overall sharpness looks the same, but of course image detail is lower. There's more aliasing at 1080p, for example.)
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