Video performance

[cmclfs]

Hi,

I’m evaluating NoMachine Terminal Server version 5.1.44-2 and the video performance is not great when playing, for instance, Youtube videos. Playback will sometimes freeze or slow down (though audio keeps playing fine and in sync), and then speed up. I have tried the playback in Chrome and Firefox, and set /usr/NX/etc/node.cfg to use h264 and vp8 (I’ve compiled the x264 lib as per the NoMachine recommendations and installed it in /usr/NX/lib/). The host is a 12 core Xeon X5650, with a Quadro M4000 (Maxwell) GPU. I’m running the applications in a rootless window. The CPU usage is about 1.5 cores worth. If I run it in a virtual desktop, the usage is about 1 full core, which seems high. I’d like to be able to support up to 10 simultaneous sessions like this on 2 cores (I’ll choose a more modern higher spec CPU though). Is that realistic?

What kind of things should I be doing to improve performance?

Thanks,

Cam

 

[fra81]

Hi Cam,

running 10 concurrent sessions all running CPU-demanding, graphics-intense applications on two cores doesn’t seem very realistic, considering that each core has to be shared between 5 sessions. Regarding the performance of the single session, you can try to turn off the ‘X11 vector graphics mode’ (Server settings -> Performance tab), thus enabling the “video” mode. The video mode is specifically designed for graphics-intense desktops and applications and for multimedia content. Also, it will allow to leverage the hardware encoding capabilities provided by your Maxwell GPU. While using the video mode, I’d also check in the NoMachine player GUI if H.264 encoding is actually in use (bring up the session menu and enter Display settings, codec info is at bottom).

[cmclfs]

Hi,

I disabled X11 vector graphics mode in node.cfg (and restarted NoMachine server), and I still get freezes occasionally when playing videos in chrome (Firefox seems ok but CPU usage is higher). I run Chrome and Firefox in ‘rootless’ mode, as it provides a cleaner interface. I couldn’t see any codec info apart from audio (see attached screenshot). Does this mean I’m not using x264?

Thanks,

Cam

 

[cmclfs]

sorry forgot the attachment…

Attachments:

1. 

   ff-displayinfo.png
   

[fra81]

Hi Cam,

sorry for delay!

Rootless sessions use a different protocol. H.264 is not used to encode all the screen, but only for encoding the videos, and that’s why it is not reported. You can check (or show us) the logs on client side to confirm that H.264 is actually used.

As for the specific problems with Chrome (and since you confirm that Firefox behaves differently), it may be that Chrome suffers for the lack of hardware acceleration. This would not be considered a NoMachine issue.

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