Terrible performance

Plex Media Server NAS & Devices
1

Recently, I have been experiencing some very poor performance. Connections are often virtually non-existent or just don’t work at all (spinning wheel with no progress made). My content is all on a NAS, which is connected to my router via cable.

Some examples of error messages are ‘Your Home Screen is empty’, ‘Something went wrong’, ‘Add content to Library’ and ‘No Libraries found’. None of these are logical, as until a week ago, everything was working fine.

Sometimes, I can get a movie/TV programme playing, only for it to grind to a halt for an unknown reason (cue more spinning wheel). Performance seems to be marginally better in the evening, as opposed to the morning. I think these problems are network-related, and I have recently had a new service and router installed, but I am at a loss to know what I can do to restore previous performance.

2

Further errors today are”

No content available Check your network connection and verify that any media servers are online.

and

app.plex.tv is unable to connect to “NAS” securely

Its “Secure connections” setting may be set to disabled, or you may need to adjust some settings on your network.

So it’s clearly network-related. But I’m still not sure how to proceed, and just feel quite tech-bamboozled. Hopefully someone can steer me in the right direction.

No settings were changed on my network since the last time everything was working ok.

3

Can we start with a copy of your server logs?

4

Here you go.

Plex Media Server Logs_2025-08-16_19-41-17.zip (4.6 MB)

5

I am not seeing anything blatantly obvious, I would verify the transcode directory as it looks a bit odd to me in the logs. However whenever I see these issues Id start with a database repair/optimization see GitHub - ChuckPa/DBRepair: Database repair utility for Plex Media Server databases

6

NAS Settings

If you change any of these settings, restart Plex Media Server.

In Synology Control Panel → Network → Network Interface, ensure the following are correct:

  • Network Address
  • Subnet Mask
  • Gateway ← usually the router IP address
  • DNS Server ← set to a public DNS such as 1.1.1.1 (CloudFlare), 8.8.8.8 (Google), 9.9.9.9 (Quad9)

In Synology Control Panel → Regional Options, ensure the NAS is synchronized with a public NTP server.

DBRepair for Plex Media Server

As @dbirch mentions, DBRepair checks the database for structural errors and also optimizes it. It is good to run it on a regular basis.

To run it on a Synology NAS:

  • Enable SSH for the NAS in Control Panel → Terminal & SNMP
  • When you run DBRepair, use the STOP AUTO START EXIT options.
# ssh to the NAS, username = your DSM login; IP = the IP address of the NAS
# On Windows run from the c:\ prompt, either CMD or PowerShell.  
# On Mac/Linux, run from a terminal sessions.
ssh username@IP

# change to the PlexMediaServer directory
cd /var/packages/PlexMediaServer/shares/PlexMediaServer

# download DBRepair.sh, -O means overwrite an existing file if one is present.
sudo wget -O DBRepair.sh https://github.com/ChuckPa/DBRepair/releases/latest/download/DBRepair.sh

# make it executable
sudo chmod a+x DBRepair.sh

# run it
sudo ./DBRepair.sh

Playback

Plex Media Server is running on a DS218play, which has an ARM CPU and does not support hardware accelerated transcoding. It should transcode 720p and some 1080p video OK, but transcoding of higher bitrate 1080p video may not work well.

Monitor playback via Plex Dashboard → Now Playing + Expanded View.

  • Is the connection local, remote, or indirect?
  • Is the video transcoding?

You should avoid transcoding video when possible, due to the limited transcoding capability of the NAS.

When streaming to a desktop/laptop, try Plex Desktop for Win/Mac/Linux instead of a web browser. Plex Desktop will direct play most video & audio formats. Web browsers have more limited playback capability. Download Plex Desktop at plex.tv.

Example:

Streaming with Safari. There is a bandwidth limit of 2000kbps. This forces Plex to transcode the video. This appears to be an indirect connection, using Plex Relay. If the device is local, then there is a local network issue. If the device is remote, then remote access is not working correctly.

Aug 16, 2025 14:22:46.078 [547466154208] DEBUG - [Req#c2/Transcode] MDE: The Plot Against America - S1 E6 - Part 6: selected media 0 / 109031
Aug 16, 2025 14:22:46.118 [547466154208] DEBUG - [Req#c2/Transcode] Streaming Resource: Calculated bandwidth of 2499kbps exceeds bandwidth limit. Changing decision parameters provided by client to fit bandwidth limit of 2000kbps
7

To add to FordGuy’s reply,

Don’t forget to reboot your modem/router and everything connected to it, including any wireless devices. That should clear any DNS cache corruption and allow everything to connect properly.

8

Thank you all, that will give me something to get my teeth into.

9

Although things seem to have improved about 2%, it’s still not right. Unfortunately, I understood only a tiny fraction of FordGuy61’s instructions, but I will endeavour to pursue them.

As he/you identified, I have a DS218play, would things be improved ‘on their own’ if I purchased a better performance NAS?

10

@ChuckPa thoughts on NAS choice?

11

I have a DS418play which I use as a development system.
It has the same processor and limited to 1 GB of main memory.
It can handle 4 drives.

When vetting the DSx18 ARMv8 models, the best stable performance achievable was 20 Mbps of 1080p H.264 encoded video (single stream without subtitle burning)

There are multiple choices HOWEVER a couple questions must be asked first

  1. How much storage is needed now?
  2. What type of media? Standard 1080p (H264) or 4K UHD (2160p) ?
  3. How much do you expect storage need to grow in a year, two years, three years ?
  4. Knowing the biggest cost of a NAS is the metal chassis, Budget ?
12

Rather than completely replacing your NAS, you might consider purchasing a mini PC to run the server and using your existing NAS for the media storage and other functions in the future. You’re generally going to get a much more powerful processor for the money.

1 Like
13

Dalmus makes a good point.

The NAS is a good NAS. Most Synology boxes lack the CPU power & features to be a good transcoding device.

For my testing here,

  1. I have a Xeon-based NAS ( which has no CPU HW transcoding capability )
  2. I have multiple mini-pc test boxes which pull media over the network from the NAS.

It’s a good solution; Good NAS + Good computational machine for PMS and transcoding.

One of my test boxes is N100 CPU based. It has AlderLake (Intel 12th Gen GPU).

I purchased it from a well known online retailer with 500GB SSD.
I later added my own 2.5" SSD for PMS database (1TB).

It can handle any playback I need to test.

14

Thanks for your replies, once again something for me to get stuck into. I notice that TV shows seem to play more easily/readily than feature films do, and playing anything through an Amazon Fire streaming box seems to be recipe for difficulties. The Plex app on my Panasonic smart TV appears to be more reliable.

15

To what is the Firestick attached? How are things connected? Is it connected to a TV, to a soundbar, etc.

Some things to check on the Firestick:

  • In the Amazon settings, what is configured for audio output? Best Available, Dolby Digital, etc. Best Available is generally the default, but is not listed on some devices.

In the Plex app on the Firestick:

Video Quality
  Adjust Automatically = Off
  Home Streaming = Maximum / Original
  Quality Suggestions = Off
  Remote Streaming = Maximum / Original
  Play smaller videos at original quality = On
Video
  Burn Subtitles = Automatic
Advanced
  Passthrough = HDMI (works for most setups)

Now, let’s see how streaming works and grab some log files.

  1. Stop Plex Media Server. Wait 30 seconds. Start Plex Media Server.
    This rolls over the log files and makes it easier to see what is happening.
  2. Wait two - three minutes for PMS to fully start and log the startup sequence.
  3. Play something using the FireStick. Do not enable subtitles.
  4. Monitor playback via Plex Dashboard → Now Playing + Expanded View.
  5. Take a screenshot of the Dashboard.
  6. Stop playback
  7. Pull the server logs (settings → troubleshooting).
  8. Upload the screenshots and the log files to the thread.

This will show us:

  • Is the connection local / remote / indirect. This can show if any network issues exist.
  • Is the video / audio direct playing or transcoding. If it is transcoding, why, and if the NAS can handle the load.

Plex Dashboard example:

xcode
xcode420×374 19 KB

16

All of that is very helpful, thanks. The Firestick(s) are attached directly to a TV HDMI port.

I will attend to this tomorrow when I have a little more time away from the kids!

17

I went through all of your instructions (In the “Plex app on the Firestick:” to parts 1 & 2 of the streaming section) but I was unable to play anything at all on the Fire box, so I don’t have any data to report on from Dashboard.

I re-started the NAS, after having shut down and restarted Plex Media Server, which was running on the NAS.

Thank you.

18

I am definitely going to look into this. I have a laptop that doesn’t get very much use at the moment, it seems that this might be the way to go. Do you have any specific links or other pointers?

19

UPDATE: I realised that my other Amazon Fire can see (and therefore play) stuff. Therefore I could finish your instructions. I have uploaded the logs and screenshot. My housemate was using the Plex app on a separate Plex account (to play ‘The Gilded Age’) on the Panasonic Smart TV at the same time as my test. I assume that that doesn’t affect my playback/data.

Plex Media Server Logs_2025-08-20_17-37-16.zip (3.7 MB)

Screenshot 2025-08-20 at 17.30.37
Screenshot 2025-08-20 at 17.30.371334×1024 111 KB

20

I have managed to play something on my Fire. Some movies won’t play, but this is an example of one that will. New set of logs.

Screenshot 2025-08-21 at 08.07.34
Screenshot 2025-08-21 at 08.07.34732×908 127 KB

Plex Media Server Logs_2025-08-21_08-08-30.zip (4.3 MB)