Solving the FPS drop of the broadcast

[AndyProfessional]

Hi, ClassicOldSong! Apollo and Artemis are excellent applications, thanks for your work.
Like many other users, I have a problem with the periodic drop in incoming frames per second from the network, while the connection itself is excellent, with a delay of 1 ms and no percentage of lost frames. Host PC is also powerful. After reading the forums for a long time and my own experience, I found out that if you set the frame rate to 120 frames per second for a 60 Hz TV in the Artemis (Moonlight) application, the periodic FPS drops coming to the client completely stop. If a 60 Hz TV is set to 60 frames per second, then there will be periodic FPS drops during the broadcast. So it seems that the 120 frames per second parameter users resources more efficiently. Other people from the Sunshine/Moonlight branch have also described similar behavior. I hope my information will help you improve your product and help other people with similar problems.

[ClassicOldSong]

There's a frame pacing option named "WarpDrive/Warp2" in Artemis, can you enable them and disable frame limit/vsync in your game and try again?

Or you can also limit framerate with RTSS.

[AndyProfessional]

Strangely enough, I don't experience much delay when setting the maximum smoothness. But if at the same time you turn on VSync in the game itself or in NVCP, then the cotton control begins and there is a noticeable delay. And when Vsync is disabled, I don't experience any special problems even with the value of "Maximum smoothness" in Artemis. And the enabled 120 FPS option heals short-term drops on client in the incoming FPS stream during the broadcast, this is the only reason why I turn on 120 FPS option in Artemis, even when I stream at 60 fps on 60Hz TV.

[ClassicOldSong]

Have you verified the behavior with other clients? TV boxes have decoders that are not commonly seen so their capablilties and behavior can't be shared with general uage.

[AndyProfessional]

I haven't tried it on other clients, but I think it's not the TV box decoder, because it's the incoming frame rate on the client that drops, not only the frame rate on the client during rendering.

[AndyProfessional]

I think it's worth paying attention to what exactly differs in the software part of the Artemis or Apollo application at 60 FPS and 120FPS. It's very similar to the full disclosure of resources, as if something stops holding back the broadcast.

[ClassicOldSong]

That report is massively inaccurate and misleading. Client decoding issue can be reported as network issues all the time.

[AndyProfessional]

OK, I accepted it. But one way or another, this method of switching to 120 FPS can help someone with similar problems (a few years ago, people had similar reports on the github forum and this solution method).

[ClassicOldSong]

Yeah, maybe I should extend warp to other frame pacing options.

[AndyProfessional]

There is another observation that when setting 60 fps in Moonlight, a short-term drop in FPS by 5-10 units (from 60 to 55-50) occurs only when starting the game via a virtual monitor (virtual desktop). When I don't run the virtual monitor, but just duplicate the monitor screen on the TV, there are no strong frame drops. So setting 120 FPS saves and is only needed when using a virtual monitor. And also the PC latency when using a virtual monitor is almost 2 times higher (50 ms versus 25). So, I still think it's the host or the software (not the TV box decoder).

[ClassicOldSong]

That's strange because most users have identical or even better latency using virtual displays. Can you verify this on other clients?

[what9000]

I will try this when I get home, and see if 120hz in artemis, 60hz on tablet, and 60hz in NVCP makes a difference. If it does, would the fix be something like programming moonlight to request double the monitor refresh rate right out of the gate, regardless of settings? I ask because this would essentially lock VDD to 60hz for me, and remove 120hz, 144hz options entirely.

[AndyProfessional]

I checked the work with another client (Xiaomi mobile android phone), and the results are identical. Short-term, rare, small FPS drops and increased PC latency (Nvidia monitoring tool) when using a virtual monitor in 60 FPS mode. Setting Moonlight to 120 FPS improves the situation, but the best solution is to simply broadcast the image from the monitor to the TV without using a virtual monitor and there is no need to enable the 120 FPS option. No significant drop in FPS and 2 times better delay time. The latest versions of Artemis/Apollo were used for testing.

[what9000]

So the most recent update to Apollo (with a fps limit in advanced options) seems to improve on the stability, but not in all cases. For low demand games like top-down 2d adventure, it is pretty much a locked 120fps. Higher demand games like system shock or final fantasy 7 rebirth seem to still cause pretty hard drops.

[what9000]

yeah, not sure what the root cause would really be. I mean I don't know the overhead of a virtual display, but it shrugs it off using a standard display or dummy plug. I'm streaming with a 4090/9800X3d at 55mbit, if people are getting away with smooth streams on apollo and artemis under different conditions I feel like there is something else at play. unfortunately, there are just so many parts that have to play nice together...

[ClassicOldSong]

Virtual display isn't introducing any overheads, instead it should have less overheads than a real monitor. The major problem here is very likely to be the clock signal isn't real in virtual display, so there's now another option to double the requested desktop framerate so you can limit with RTSS. It's reportedly solving the problems on some systems.

[what9000]

I did set my panel to 60hz on the y700, frame cap of 60 in rtss (also tried 60 in nvcp) and 120hz request in moonlight, but it was a bit of a disaster. The stream was just all over the place with frame pacing and judder. I will try again sometime this week and use a wired connection just to eliminate any wifi shenanigans. I wonder if that's something that could be incorporated into the client though, essentially requesting 2x the native panel refresh.

[ClassicOldSong]

It's now in alpha.4, you can enable the double refresh rate option in Apollo.

The key seems to be RTSS, but whatever I do with my setup, they're just smooth. Probably my games aren't that demanding but I don't have these games frequently reported with problems to test.

[what9000]

It doesn't help that the latest Nvidia drivers appear to be a bit of a mess, as does windows 24H2 which my office PC automatically updated to. Thanks for the quick update to alpha 4, I'll try that tonight and report back.

[what9000]

Holy cow I think that did it. Selecting 2x refresh rate in the new alpha 5, I ran through system shock at a nearly completely locked 144fps. I also installed it on my main pc and final fantasy 7 also seemed locked in. I'll run more testing tonight to see if it holds up over extended plays, but so far this seems to have solved it. Excellent work!