I am experimenting with Nvidia Smooth Motion having finally acquired my first gaming monitor (nothing remotely fancy compared to what most people here use - just a humble Gigabyte G27QC). The smooth motion itself actually works perfectly - way better than I could even have imagined however it does seem to come at a cost of a minuscule additional amount of latency though on reflection the amount is so small I think it is more of a nocebo effect than anything of true significance. I did actually "claw back" most of the additional latency by reducing pre-rendered frames from 2 to 1.

I'm thinking of using it permanently if I still like it after a couple of weeks testing however there is one immediate problem I have been unable to solve. Whenever I have Smooth Motion enabled, if I access anything through the P3D menu interface after I have loaded my desired scenario, the screen will go black for perhaps 2 seconds then the normal image will return. So for example if I wish to select a weather theme, the screen goes black when I go to select it. It also happens whenever I access the kneeboard plus there is another example whereby if I have any 2D panel (say a GPS) that is partly underneath the ATC window, that also gives me 2 seconds of black screen if I do a mouse click anywhere on the ATC Window (at least I could do a workaround for that one by re-locating the GPS 2D panel if I had to).

All these issues 100% go away when Smooth Motion is turned off and 100% return if it is turned on. It is obviously very annoying since I will often encounter these particular scenarios that cause the screen to go black, especially the kneeboard problem.

I couldn't really find anything on this doing a search and not much if anything on the internet either (though that could simply be the fact that P3D has a very small user base in the overall scheme of things and not many users likely use Smooth Motion).

Anyway, I am out of ideas to try though I have honestly just been randomly trying things stabbing in the dark (including using a frame rate limiter, changing the Windows settings so that it users or doesn't use windowed optimisations, etc). There is possibly some simple setting somewhere that solves it and it has just eluded me (apart from turning Smooth Motion off!).

Perhaps it is an Nvidia driver issue and I should try to submit a bug report to them?

Hi @JonP01,

You don't mention the GFX card model or the NVidia driver version in use, however seeing as NVidia Smooth Motion was introduced originally for 5000 series cards and has been backported for 4000 series cards one would assume either a 5000 or 4000 series.

Some general info for those to whom the term "Smooth Motion" is an item of unfamiliarity, essentially its NVidia's version of universal Frame Generation built into their driver package.

https://www.nvidia.com/en-au/geforce/news/nvidia-app-global-dlss-overrides-rtx-40-series-smooth-motion/ 

Going by redit denizens, NVidia Smooth motion has its issues, which will no doubt either be gradually overcome or SM will be dropped for some other technology that will eventually replace it.

Have you trialed Lossless Scaling at all ?

Given my GPU is a 3080ti I've no options for trialing smooth motion, however I've found LS works fine for myself where I use it not only on P3D but also many games.

2 x clips, a short panning clip of LS in action and a longer flying clip, top left is the LS frame generation enhanced frame rate and bottom right is the fps P3D is locked at. 

Cheers 

 

Edited February 4Feb 4 by Rogen
expanded

Thanks for the reply. I haven't actually looked into lossless scaling - I will have to get my mind around it - I already use DL DSR 2.25x so I am not sure how it would work with that. I am extremely happy however with how Smooth Motion works - to be honest I am gobsmacked and in awe of it since in years gone by I have looked at frame generation tecnologies and they were appalling. But Smooth Motion has - on my setup at least -  absolutely zero - and I mean truly zero - artefacts. If I were doing blind testing there is no possible way I would be able to correctly identify the smooth motion versus having a fictitious computer literally twice as fast as the one I own. My card is an RTX4080 Super btw so yes, Nvidia did indeed make it available for 50x series followed by 40x series soon after.

I actually only fly smaller GA with the two exceptions being the A2A Connie and Carenado Fokker F50. Those combined with eschewing overly "big city" complex scenery (I just stick to the relatively smaller ORBX add-ons and most of their regional packs), I had P3D running at a perfect 50 fps 99.99% of the time (the only time it ever deviated from 50 fps was the very slight singular pauses (maybe 1/10th of the second to 1/4 second at the very worst) whenever my aircraft entered a "new" ORBX scenery area. I would just get that one very small tiny pause and that was it.

But since there is some overhead with Smooth Motion after some experimentation I settled on a base frame rate of 47 and then set up a custom resolution / refresh rate of 94 Hz (when I tried 50 / 100 there was clearly too many instances of it no longer being able to maintain that 50 fps base rate and thus the Smooth Motion suffered - it needs perfect smoothness at the base rate for it to work properly without any issues. With smooth motion and a base rate of 47 fps though, I get 94 fps 99.99% of the time as I got 50 fps 99.99% of the time without it.

It is only the momentary black screens that are an annoyance but they are not enough for me to quit using it since as a sim racer and occasional fps indulger, I know the enormous benefits of high frame rates when it comes to clarity when panning.

With P3D, these high frame rates don't do anything (at least for me) when taking off or landing or even when cruising - that 50 fps doesn't already do - they just bring a very tangible and welcome benefit - when panning around.

But I will look into your suggestion - those videos you linked to are doing the same thing as what I get in terms of high fps smoothness - the only difference is yours is at 60 fps and mine is 94 fps but as mentioned, I prefer flying in simple scenarios and was happy to turn some stuff down to get that original 50 fps to begin with.

I was able to solve the problem for anyone interested, however the solution doesn't really make any sense since I had to change two settings that shouldn't have mattered.

Even though I am not using G-SYNC for Prepar3D and thus had the Nvidia Control Panel setup for Prepar3D as:

Monitor Technology: Fixed Refresh Rate

(and also reflected as such in my Nvidia Inspector profile for Prepar3D), the "solution" was to instead change the Nvidia Inspector settings to:

G-SYNC - Application Requested State to Force Off (was previously Fixed Refresh Rate as per Nvidia Control Panel)

G-SYNC - Application State to Force Off (was previously Fixed Refresh Rate as per Nvidia Control Panel)

The above two changes then resulted in the equivalent Nvidia Control Panel setting changing to:

Monitor Technology: Not supported for this Application (and everything on that entire line becomes greyed out meaning that I could not have implemented these settings using Nvidia Control Panel only).

And after I did that, Prepar3D now works perfectly - no screen blackouts whatsoever - just perfect and Smooth Motion giving me 94 fps 99.99% of the time.

Now why this should have fixed the problem when I already had G-SYNC set to Fixed Refresh Rate and the same in Nvidia Inspector is a bit beyond me. It should have fixed any potential problem before it became a problem to begin with but for some reason I need to actually force G-SYNC off completely even though as I say I don't use it for Prepar3D anyway.

The other weird thing is that if I go to turn off G-SYNC globally (via the Nvidia Control Panel Global 3D Settings) and then enable it only for the applications I do actually use it with, it no longer works properly in those applications - there is some minor but evident stuttering whereas when it is turned on globally it is absolutely 100% flawless.

This is another case it seems of Nvidia Inspector saving the day even though the Nvidia Control Panel should have resolved the problem on its own. And I have t wonder whether this is a bug that is "bigger" than Prepar3D and might be a reason so many people have complained that G-SYNC causes stuttering (whereas on my setup it works flawlessly with absolutely zero stuttering).

I should add that if I change the G-SYNC setup in Nvidia Control Panel so it is turned off there, that also "solves" the Prepar3D black screen problem however than means I have to keep turning it on or off all the time depending on what 3D application I am running. Obviously my solution above means I can just set it once and forget it.

To be fair to Nvidia, it could be something related to how my monitor works (it is officially G-SYNC compatible but not G-SYNC Certified). So to be fair I will just say on my system with my setup and my monitor, this is the solution that worked for me!

I just thought I might add as an interesting aside to frame rates and "doubling". Prepar3D one could argue actually saw it earliest genesis in Combat Flight Simulator 2 (CFS2) that preceded FS2002 by a year or two. It was in CFS2 that Microsoft decided to go all out with a massively revised engine after the terrible bagging that flight simmers gave to FS2000. CFS2 was their first retail "test bed" and I often wonder if they chose the Pacific region because it was light on the scenery! I remember FS2000 well - it was just a hopeless stutter-fest and it did not seem to matter what hardware you threw at it (remembering that back then you could buy hardware twice as fast as what you currently had every 6 months or so!).

I remember reading about this somewhere (I do not remember where) but Microsoft were extremely vigilant in creating a new engine that did its best to maintain a target frame rate and was willing to sacrifice the rendering quality of the scenery to maintain it. That is how the whole thing of the blurries started. With FS2000 there were no blurries but we started getting them from CFS2 onwards and by FSX (because of the ever increasing computing hardware requirements) they got worse before they finally started to of course get better again to the point where now we have P3D that is so highly evolved from those roots, blurries don't even cross our minds anymore.

But as for frame doubling, many simmers did not realise that with CFS2 and FS2002, if you were running, say vsync at 75 Hz and the reported frame rate (using the usual red text info up the top was also saying 75 fps, you actually were not getting 75 actual individual frames - you are only getting precisely half that. It was not until FS2004 that what you saw on the frame rate readout was what you were actually getting on the screen. My precise memory is a bit flaky but I seem to recall this half frame rate thing also occurred on FS98 and FS2000 as well (I only took up flight simming from FS98 so can't speak of earlier versions).

Oen reason I bring this up is because by the time FS2004 came out, I never had a computer fast enough to run it at the same frame rate as the monitor refresh rate anyway - so I always settled for half which on an 85 Hz CRT gave me around 43 fps. So this is the first time in 28 years of using only the flight sims based off those original Microsoft products where I am seeing for the first time what a high frame rate actually looks like in a flight sim! Before this Smooth Motion, the best I ever managed was 43 fps until I build my new (for mid 2024) machine when I then managed to tune it to 50 fps at 50 Hz. But now at 94 fps it really is wonderful - I can pan around and although there is still obviously motion blur, it is massively reduced (I shudder to think what sort of frame rate I would need to no longer perceive motion blur during panning but it would need to be something insanely high as I am very sensitive to motion blur!). 

 

Bear in mined drivers are often updated to address issues for Monitors or TV panels that are found by feedback. Two PCs using the same GPU can have a different problem caused by the display or settings being used. I seen drivers addressing HDR issues causing black screen on some manufactories screens.