Do I have a bottleneck somewhere? HDHomerun, QNAP NAS, Nvidia Shield

[Curtz 2]

For reference I have Emby Server on my QNAP TS-251 NAS and am recording antenna TV from my HDHomerun Flex to the NAS. I'm then using the Emby app on my Nvidia Shield TV Pro to view live and recorded TV. All are hard-wired with ethernet cable to a TP-Link TL-SG105 Gigabit network switch which in turn is hard-wired to a Centurytel provided DSL modem/router. My sorry DSL internet runs at a maximum of 10mbps. 

The problem or bottleneck I'm running into is when I rewind or fast forward recorded TV. Sometimes it's nearly instant like my Dish Hopper system, but most of the time I have to wait and wait while being entertained by the swirling icon. Is this normal, or do I have a bottleneck somewhere?

The NAS has standard (not solid state) WD Red hard drives. Are these too slow perhaps?

Even though the entire system is hard-wired, does my slow 10mbps internet somehow affect my speed? 

[justinrh 175]

Internet is not a factor, since you are on the LAN.  It very well could be a combination of drive and CPU performance.  Can you monitor either resource on your NAS?

Edited December 15, 2021 by justinrh

[Curtz 2]

I am able to monitor it and will do so next chance I get. Thanks. 

[Luke 37232]

2 hours ago, Curtz said:

I am able to monitor it and will do so next chance I get. Thanks. 

Let us know what you find. Thanks.

[Curtz 2]

Last night I watched parts of the Packer/Bears game that I had previously recorded. It had been recorded using Plex so I could have it mark the commercials. I played it back using Emby and then Plex with similar results. When I rewinded or fast-forwarded through the recording, there were times when it was nearly instant, and times I had to wait for perhaps up to 10 seconds. While I did this, I used the QNAP resource manager app on my phone for roughly 5 minute intervals to monitor the CPU usage. It's clear that rewinding and fast-forwarding caused CPU usage to increase, but I'm not sure if the results below show anything in excess that would cause the issues I'm having.

Note also that I watched the 3 hour Survivor finale last night while it was also recording (I was about an hour behind) and I was able to fast-forward and rewind nearly flawlessly. This was again using Plex because I do all my recordings through Plex because it's able to mark commercials for skipping. 

The first photo is while using Plex and the second is while using Emby.

Edited December 16, 2021 by Curtz

[Luke 37232]

Plex runs multiple processes, so you can't really compare CPU usage between the two unless you're going to add up all of the usage by all of it's processes.

[Curtz 2]

I only showed both because I was curious if either Plex or Emby used more resources when playing back recordings from my NAS. I figured I might as well show both screenshots. Perhaps I'm wrong, but it doesn't appear to me that the bottleneck, if there is one causing slow responses, is the fault of my NAS. 

Any thoughts? 

[justinrh 175]

disk I/O?

[Carlo 4331]

@Curtz 

You have the 251 model and not the 251+ correct?
If so it has a 2.41 GHz Intel Celeron J1800 CPU.  This is more or less a cross between the Atom and Celeron line. It has 2 cores and 2 total threads as well as supporting QuickSync but only has an Intel® HD Graphics for Intel Atom® Processor Z3700 Series integrated GPU.

I don't really know anything about this particular NAS but just did a quick read on it's review here: https://www.smallnetbuilder.com/archives/nas/nas-reviews/32503-qnap-ts-251-ts-451-turbo-nases-reviewed?start=0

Based on the chipset this NAS uses what you describe with the delay during playback is not surprising at all and we may not be able to improve things too much, but let's take a look.

Can you do a quick test for us?
Play back the Packers game again for 2 or 3 minutes using the same Emby Client you did the other day.
Now on the Web dashboard go down to the logs menu and select it.  Do you see a file with the date/time at the top that matches the time you just played this back.
Download that ffmpeg file as well as the server log (file at top of list). If there is multiple ffmpeg logs with that date/time grab them all.

Next go to the Transcoding menu and click on that.  If the first option isn't already set to Advanced, please change it to that.  Now you will see more information on the page.  Please take a couple shots of the options being shown.

Now upload the logs and screen shots from the transcode menu.
This will let us see how the Packers game was being played back plus see if your transcoding is optimized as best it can be.

Thanks,
Carlo

 

[Curtz 2]

Yes, it's the TS-251, not the plus model. For what it's worth, I did add more RAM to the max it would take. 

I'll do the test you mentioned when I get back home.

Thanks! 

[Carlo 4331]

Let us know when you get a chance to take a look at this.