The PC client (Windows Pro X64) takes a lot of CPU for me, around 30-40% for over an hour after starting up the client. I looked through the log file and at around 19:40 (7:40 pm) it had finished going through my videos, but for over an hour after that it kept using the same amount of CPU, and then I turned it off around 21:00 (9 pm).

I noticed though that the CPU load, decreased to close to 0% when the application was minimized, but as soon as I maximized it again, the CPU was at around 30-40%. No one was connected to the PC client at the time of this test and no video was playing. So it seems that it is using way to much CPU for just being visible on the screen. I should probably add that I run SkyBox in a VirtualBox VM.

Here is the end of my log file from that time, and it does not seem like it is doing much beween 8pm and 9 pm, so it must be just the drawing of the application I guess:

Sat Sep 22 2018 19:42:48 GMT+0200 (W. Europe Daylight Time) updateServerMediaList
Sat Sep 22 2018 19:42:48 GMT+0200 (W. Europe Daylight Time) getLoggedInSocketsWithPort: []
Sat Sep 22 2018 19:42:48 GMT+0200 (W. Europe Daylight Time) sendCommandToAll
Sat Sep 22 2018 19:42:48 GMT+0200 (W. Europe Daylight Time) sendCommandToAll: 9900
Sat Sep 22 2018 19:42:48 GMT+0200 (W. Europe Daylight Time) getLoggedInSocketsWithPort: []
Sat Sep 22 2018 19:42:48 GMT+0200 (W. Europe Daylight Time) debug from renderer: "updateVideoList: list length--479"
Sat Sep 22 2018 19:42:48 GMT+0200 (W. Europe Daylight Time) debug from renderer: "updateVideoList: list: updated!"
Sat Sep 22 2018 19:42:48 GMT+0200 (W. Europe Daylight Time) streamer: stdout--updateServerMediaList: 9900

Sat Sep 22 2018 19:42:48 GMT+0200 (W. Europe Daylight Time) server: stdout--_updateReadyMediaToClients: sockets is empty

Sat Sep 22 2018 19:44:07 GMT+0200 (W. Europe Daylight Time) saveCacheFile
Sat Sep 22 2018 19:45:06 GMT+0200 (W. Europe Daylight Time) GPU memory info: 3180, {"workingSetSize":122544,"peakWorkingSetSize":149552,"privateBytes":97956,"sharedBytes":30672}
Sat Sep 22 2018 19:48:07 GMT+0200 (W. Europe Daylight Time) saveCacheFile
Sat Sep 22 2018 19:50:06 GMT+0200 (W. Europe Daylight Time) GPU memory info: 3180, {"workingSetSize":107952,"peakWorkingSetSize":149552,"privateBytes":102292,"sharedBytes":24480}
Sat Sep 22 2018 19:52:07 GMT+0200 (W. Europe Daylight Time) saveCacheFile
Sat Sep 22 2018 19:55:06 GMT+0200 (W. Europe Daylight Time) GPU memory info: 3180, {"workingSetSize":97040,"peakWorkingSetSize":149552,"privateBytes":103320,"sharedBytes":13508}
Sat Sep 22 2018 19:56:07 GMT+0200 (W. Europe Daylight Time) saveCacheFile
Sat Sep 22 2018 20:00:06 GMT+0200 (W. Europe Daylight Time) GPU memory info: 3180, {"workingSetSize":90112,"peakWorkingSetSize":149552,"privateBytes":107620,"sharedBytes":3384}
Sat Sep 22 2018 20:00:07 GMT+0200 (W. Europe Daylight Time) saveCacheFile
Sat Sep 22 2018 20:04:07 GMT+0200 (W. Europe Daylight Time) saveCacheFile
Sat Sep 22 2018 20:05:06 GMT+0200 (W. Europe Daylight Time) GPU memory info: 3180, {"workingSetSize":91508,"peakWorkingSetSize":149552,"privateBytes":109992,"sharedBytes":3388}
Sat Sep 22 2018 20:08:07 GMT+0200 (W. Europe Daylight Time) saveCacheFile
Sat Sep 22 2018 20:10:06 GMT+0200 (W. Europe Daylight Time) GPU memory info: 3180, {"workingSetSize":94196,"peakWorkingSetSize":149552,"privateBytes":112912,"sharedBytes":3388}
Sat Sep 22 2018 20:12:07 GMT+0200 (W. Europe Daylight Time) saveCacheFile
Sat Sep 22 2018 20:15:06 GMT+0200 (W. Europe Daylight Time) GPU memory info: 3180, {"workingSetSize":96632,"peakWorkingSetSize":149552,"privateBytes":115364,"sharedBytes":3388}
Sat Sep 22 2018 20:16:07 GMT+0200 (W. Europe Daylight Time) saveCacheFile
Sat Sep 22 2018 20:20:06 GMT+0200 (W. Europe Daylight Time) GPU memory info: 3180, {"workingSetSize":99916,"peakWorkingSetSize":149552,"privateBytes":117444,"sharedBytes":4256}
Sat Sep 22 2018 20:20:07 GMT+0200 (W. Europe Daylight Time) saveCacheFile
Sat Sep 22 2018 20:24:07 GMT+0200 (W. Europe Daylight Time) saveCacheFile
Sat Sep 22 2018 20:25:06 GMT+0200 (W. Europe Daylight Time) GPU memory info: 3180, {"workingSetSize":103048,"peakWorkingSetSize":149552,"privateBytes":121116,"sharedBytes":4968}
Sat Sep 22 2018 20:28:07 GMT+0200 (W. Europe Daylight Time) saveCacheFile
Sat Sep 22 2018 20:30:06 GMT+0200 (W. Europe Daylight Time) GPU memory info: 3180, {"workingSetSize":105552,"peakWorkingSetSize":149552,"privateBytes":123140,"sharedBytes":4968}
Sat Sep 22 2018 20:32:07 GMT+0200 (W. Europe Daylight Time) saveCacheFile
Sat Sep 22 2018 20:35:06 GMT+0200 (W. Europe Daylight Time) GPU memory info: 3180, {"workingSetSize":107952,"peakWorkingSetSize":149552,"privateBytes":126112,"sharedBytes":4968}
Sat Sep 22 2018 20:36:07 GMT+0200 (W. Europe Daylight Time) saveCacheFile
Sat Sep 22 2018 20:40:06 GMT+0200 (W. Europe Daylight Time) GPU memory info: 3180, {"workingSetSize":110532,"peakWorkingSetSize":149552,"privateBytes":129604,"sharedBytes":4968}
Sat Sep 22 2018 20:40:07 GMT+0200 (W. Europe Daylight Time) saveCacheFile
Sat Sep 22 2018 20:44:07 GMT+0200 (W. Europe Daylight Time) saveCacheFile
Sat Sep 22 2018 20:45:06 GMT+0200 (W. Europe Daylight Time) GPU memory info: 3180, {"workingSetSize":113340,"peakWorkingSetSize":149552,"privateBytes":132920,"sharedBytes":5156}
Sat Sep 22 2018 20:48:07 GMT+0200 (W. Europe Daylight Time) saveCacheFile
Sat Sep 22 2018 20:50:06 GMT+0200 (W. Europe Daylight Time) GPU memory info: 3180, {"workingSetSize":115844,"peakWorkingSetSize":149552,"privateBytes":136284,"sharedBytes":5156}
Sat Sep 22 2018 20:52:07 GMT+0200 (W. Europe Daylight Time) saveCacheFile
Sat Sep 22 2018 20:55:06 GMT+0200 (W. Europe Daylight Time) GPU memory info: 3180, {"workingSetSize":118276,"peakWorkingSetSize":149552,"privateBytes":138556,"sharedBytes":5156}
Sat Sep 22 2018 20:56:07 GMT+0200 (W. Europe Daylight Time) saveCacheFile
Sat Sep 22 2018 21:00:07 GMT+0200 (W. Europe Daylight Time) GPU memory info: 3180, {"workingSetSize":128048,"peakWorkingSetSize":156228,"privateBytes":138708,"sharedBytes":10944}
Sat Sep 22 2018 21:00:07 GMT+0200 (W. Europe Daylight Time) saveCacheFile
Sat Sep 22 2018 21:04:07 GMT+0200 (W. Europe Daylight Time) saveCacheFile
Sat Sep 22 2018 21:05:07 GMT+0200 (W. Europe Daylight Time) GPU memory info: 3180, {"workingSetSize":129484,"peakWorkingSetSize":156228,"privateBytes":141688,"sharedBytes":10944}
Sat Sep 22 2018 21:08:07 GMT+0200 (W. Europe Daylight Time) saveCacheFile
Sat Sep 22 2018 21:08:50 GMT+0200 (W. Europe Daylight Time) mainWindow.close
Sat Sep 22 2018 21:08:50 GMT+0200 (W. Europe Daylight Time) PowerSaveBlocker: stop: powerSaveBlocker not started!
Sat Sep 22 2018 21:08:50 GMT+0200 (W. Europe Daylight Time) app.window-all-closed
Sat Sep 22 2018 21:08:50 GMT+0200 (W. Europe Daylight Time) before-quit
Sat Sep 22 2018 21:08:50 GMT+0200 (W. Europe Daylight Time) sendCommandToAll
Sat Sep 22 2018 21:08:50 GMT+0200 (W. Europe Daylight Time) sendCommandToAll: 9900
Sat Sep 22 2018 21:08:50 GMT+0200 (W. Europe Daylight Time) app.quit: {"sender":{"domain":null,"events":{"quit":[null,null]},"eventsCount":11,"commandLine":{}}} 0
Sat Sep 22 2018 21:08:50 GMT+0200 (W. Europe Daylight Time) mainWindow.closed
Sat Sep 22 2018 21:08:50 GMT+0200 (W. Europe Daylight Time) saveCacheFile
Sat Sep 22 2018 21:08:50 GMT+0200 (W. Europe Daylight Time) disconnectAll: 0
Sat Sep 22 2018 21:08:50 GMT+0200 (W. Europe Daylight Time) server: err--{"code":"EPIPE","errno":"EPIPE","syscall":"write"}
Sat Sep 22 2018 21:08:50 GMT+0200 (W. Europe Daylight Time) PowerSaveBlocker: stop: powerSaveBlocker not started!
Sat Sep 22 2018 21:08:50 GMT+0200 (W. Europe Daylight Time) imageprocessing: stdout--_handleParentMessage: exitProcess
IMAGEPROCESSING_PLUGIN_PATH--C:\Program Files\skybox\resources\app.asar.unpacked\deps\df-sdk-win-x64\Skybox.dll
ImageProcessing::getDesc