Low FPS issue streaming from Linux

[bwyazel]

Hello,

I have NoMachine set up on my server, which is a 24core PowerEdge with a Titan Xp GPU. I have h.264 hardware encoding through NVENC successfully set up, and it works awesome! My issue is that even though through the server config I have it set to stream 60fps, it feels like it’s actually more like 20fps, with dragging and moving windows being super jumpy and there is no fluidity to the desktop at all.

Any ideas what could be causing this or how to fix it? I’ve updated both the clients and servers to the newest release, and the server is running on Ubuntu 17.10 with Gnome and the latest 390 Nvidia Drivers

[fra81]

Hello,

for sure your hardware should be able to stream 60 fps without problems! What is your client side hardware and OS? And would you exclude bandwidth problems? For example, does it get any better if you lower the Display quality in the Display settings menu?

Additionally you could send us the logs, so we can search for any hints. For the server side: https://www.nomachine.com/AR10K00697. For client side: https://www.nomachine.com/DT10O00163#2. You can send them to forum[at]nomachine[dot]com.

[bwyazel]

Client side is Archlinux with an i7 6700k (running HD 530 graphics) with vaapi and vdpau verified and set up for hardware accelerated decoding.

Bandwidth internally is constant gigabit ethernet, eith steady ping of 0.75ms +-.05ms. Externally, the university is connected with gigabit down and gigabit up, and my home connection (for when I’m not connecting from my office) has 150mb/s down. I don’t think bandwidth is the problem, as i’m reporting only 750kb/s – 2mb/s at any point in time uploading from the server when I’m using it.

This issue shows up when connecting to the same server from three different computers, two on archlinux, one with intel graphics, one with AMD graphics, and a third computer running Windows7 with Nvidia graphics. I wouldn’t think it’s a client issue based on the consistency of these behaviors.

Lowering the display quality has no noticeable improvement on the fps.

Btw, the server is running Ubuntu 17.10 with Gnome3.26, using the Xorg session, with Nvidia drivers 390.25. I’m emailing the logs now.

Attachments:

1. NoMachine-log.tar-1.gz
2. nxdir.tar.gz

[Britgirl]

Hi, the logs didn’t help us to identify the problem, so we’ve just sent you a debug package which will help us to narrow down the issue. Please install on the server side, reproduce the problem and send us the logs 🙂

[bwyazel]

Here are the server side logs for the debug package that you sent. Did you need the client side as well?

Attachments:

1. NoMachine-log.tar.gz

[fra81]

Hi,

sorry for the delay. I really thought I had already answered!

As one may expect, in the logs I see that NoMachine on your hardware is really capable to produce 60 frames per second, or vey close to that (the second number is fps):

R 17.7/56.4
R 17.4/57.5
R 17.5/57.1
R 17.8/56.2
R 17.3/57.8

In particular, I see that around 57 frames per second are produced steadily at least for some time, until congestion (or a significative increase of network latency) is detected on the network:

42417 42970 11:26:53 522.772 DisplayServer/DisplayServer: Received congestion message with level 9.

At that point, as expected, the server decreases the frame rate.

All in all, I really think the reason is to be find in the network conditions, and not in any hardware or algorythmic issue, that seem to be excluded when looking at the logs.

[bwyazel]

Hi, I think I’m tracking down this fps issue a bit better. It has to do with the resolution it seems. Sometimes when I log in now I will be streaming the perfect 60fps, but if I try to adjust the resolution at all through the NoMachine control panel, the resultant stream will have a low fps. However, if I toggle the fps within Gnome-control-center to something else, the fps will go back to 60fps. (though this isn’t 100%, sometimes I can not get the fps to go back to 60fps unless I kill the connection and reconnect. Also, sometimes adjusting the resolution doesn’t effect the fps.) It is really finicky.

[fra81]

Hi,

indeed screen resolution will affect both CPU usage (but we already concluded that CPU is not an issue for you) and network bandwidth usage. What you say seems to confirm further that network should be the culprit here.

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