NAS 4k issues (NAS/unnraid/Plex)

[Pug]

Hi chaps

My issue is sometimes my 4k UHD videos (h265 or h264) can mostly play fine, and other times they are constantly buffering, few secs playing then buffering. Could my N40 be struggling to feed the other devices in my setup (is that likely?). It's by far the oldest/most underpowered part, but in terms of reading I didn't figure a 4k file to be THAT arduous for a SATA drive. Example tonight was a 4k HDR 30mbps file. Kept dropping in and out after half way through.

My setup:

• HP N40L micro server running unraid, with 4x2 TB SATA HDDs (1 used for parity) connected to gigabit switch
• Intel NUC i3 (ssd win10, 4GB RAM) running as a plex server connected to gigabit switch
• LG 65 OLED TV, Plex client, connected to gigabit switch

Movies played are (to my knowledge) compatible with client to avoid it transcoding, so I think it is now a network issue, but am open to suggestions.

I should say my disks are nearly full (90%+ if that matters?)

It's not every file at the same place, is more like something else is happening in the background and it can't do both (no other Plex streams, just maybe other disk access?). That said super detailed 4k scenes can also trip it up. As I write this now, I'm wondering if it's not the NAS but the client..

 

[JohnG7]

Plex can have poor performance (not sure if that has changed in past year or so), try Emby.

A HDD being near full could effect it for sure.

 

[HungryHippos]

TV Plex Client is likely transcoding it.

You can see what is doing what on your current streaming from the Plex server dashboard. http://localplexip:32400/web/index.html. Top right click the little heartbeat icon next to the spanner, then dashboard.

As a bit of general advice don't get the encoded films, they are smaller but will need CPU power to play them which NAS will lack. Get full fat remux files for direct play compatibility.

TV Plex client is a bit weak as well, for a client device I use an Nvidia Shield TV.

 

[Pug]

TV Plex Client is likely transcoding it.

You can see what is doing what on your current streaming from the Plex server dashboard. http://localplexip:32400/web/index.html. Top right click the little heartbeat icon next to the spanner, then dashboard.

As a bit of general advice don't get the encoded films, they are smaller but will need CPU power to play them which NAS will lack. Get full fat remux files for direct play compatibility.

TV Plex client is a bit weak as well, for a client device I use an Nvidia Shield TV.

To be clear the NAS is just providing the file, my i3 NUC is doing the "serving", and the TV's play HEVC (265) natively from usb (with zero issues)

 

[Pug]

Plex can have poor performance (not sure if that has changed in past year or so), try Emby.

A HDD being near full could effect it for sure.

Thanks, I'll try cleaning the HDDs and see. I'm pretty invested in Plex (multiple clients, tablets, offline for work trips etc). I can move on, but need to be totally fed-up of it. I'll try playing them over dlna to my TV client to perhaps circumvent Plex first.

 

[Pug]

So did a v small test this morning and I think (too soon to be sure) I've solved my issue. It was either the library running updates when watching causing the NAS to be overused, or me having a bigger setup in Plex thinking it was helping.

Apparantly the buffer may have been causing the server to choke, and then pause whilst the buffer refilled... So doing the opposite of what I wanted.

I'll see and report back. Thanks for the input.

 

[HungryHippos]

I've seen issues with the TV plex client transcoding when USB can play fine, so it's just how the client handles the file.

Have you checked the dashboard for what it's doing when it's choking?

As you can see mine is transcoding this example.

 

[Pug]

Hhhm weird.

I haven't checked that yet as it hasn't buffered yet. If (when) it does I'll check, thanks.

 

[HungryHippos]

Hhhm weird.

I haven't checked that yet as it hasn't buffered yet. If (when) it does I'll check, thanks.

When you play the file and check the dashboard I'm interested as to what that says for you and what it's doing, mainly to satisfy my curiosity at this point

 

[Pug]

When you play the file and check the dashboard I'm interested as to what that says for you and what it's doing, mainly to satisfy my curiosity at this point

 

[HungryHippos]

Cool OK maybe the buffering was caused by bandwidth issues then? Direct Play won't use like any processing power at all, but does rely on the data being sent over quickly enough.

I have also noticed from using Plex on TV that it's not as good at caching. I have some content I can't play on my Plex via TV at all as it simply won't pre-cache it properly, which will play just fine on my Nvidia Shield TV Plex app.

 

[Pug]

Pretty sure I was forcing a transcode by having my Plex client buffer more than it needed. Will try to replicate tonight and see.

 

[Bindlestiff]

How did you get on? I've got a similar issue that I've semi sorted but it meant I had to roll back the server version to 1.16.6.1592. I've not upgraded since, which is not ideal, but the buffering definitely reduced dramatically.

 

[Bindlestiff]

Apologies, forum seemed to not accept the first post.

 

[Avalon]

Pretty sure I was forcing a transcode by having my Plex client buffer more than it needed. Will try to replicate tonight and see.

Instead of pulling theories out of thin air can we get some facts? What specific model of TV and NUC? Many smart TV's come with a 100Mbit port (check the switch for the port status), if so good luck fitting 121Mbit (as per your screenshot) down a 100Mbit pipe. Failing that have you got PlexPass? Just if not, no i3 NUC will transcode 121Mbit 4K HDR HEVC in software, that's 17k+ of CPU mark, even the 10th gen 10110U only manages 4k+ of CPU mark, so it's certainly not doing that. iGPU and HW transcoding could do 4K to 1080p, but you'd presumably notice the horrors of 4K HDR to 1080p SDR if that was happening? Also how were you altering client buffering on direct play from the client side?

 

[Pug]

Sorry for the delay, I've been away.

Instead of pulling theories out of thin air can we get some facts? What specific model of TV and NUC? Many smart TV's come with a 100Mbit port (check the switch for the port status), if so good luck fitting 121Mbit (as per your screenshot) down a 100Mbit pipe. Failing that have you got PlexPass? Just if not, no i3 NUC will transcode 121Mbit 4K HDR HEVC in software, that's 17k+ of CPU mark, even the 10th gen 10110U only manages 4k+ of CPU mark, so it's certainly not doing that. iGPU and HW transcoding could do 4K to 1080p, but you'd presumably notice the horrors of 4K HDR to 1080p SDR if that was happening? Also how were you altering client buffering on direct play from the client side?

LG OLED 65 B7V
Nuc: D34010WYK (i3-4010u)
Switch lights (GS208) all green
Plex pass lifetime member
Deffo 4k deffo HDR
Latest server version (1.19.5.3112)

I went into the plex server settings and set library scan interval to daily (in case I was overloading the NAS with too frequent scans) and I forget the exact buffering setting I changed, nothing jumps out now.u I but ittit might have been "transcoder default throttle buffer".

I think in the past I had set this to a higher number (theory being it was better to have a bigger buffer) but in reality the buffer was forcing the NUC/NAS to buffer when it was better to just pass it through.

No expert, and could be wrong. Aside from the start of watching I now never get buffering on 4k HDR high bitrate files.

 

[Avalon]

Altering the scan interval could only have any effect if the scan was running at the time you had issues. Also as you say you aren’t transcoding, altering the transcoding settings isn’t going to help either, that particular setting is the number of seconds that your NUC (if it were transcoding) would encode before easing off and will have zero impact on not transcoding.

A quick google suggests B7 and the year after’s C7 have 100Mbit ports, if you’re playing 125Mbit/s (eg a 100GB REMUX which specifies 128Mbit as the upper limit for 100GB discs and 108Mbit for 66GB discs) as per that screenshot, that would explain your issue.

 

[HungryHippos]

Yes to me this sounded like a bandwidth issue as well.

 

[Pug]

But I haven't changed my TV, switch or cabling. No hardware has changed, so I can't agree.

Perhaps my scans were running too frequently, perhaps another setting got changed, unsure, but it's not a bandwidth issue (for me).

There isn't some compression at play here? The example above is a HEVC file, so it's it transferring a125mbps stream?

 

[Avalon]

But I haven't changed my TV, switch or cabling. No hardware has changed, so I can't agree.

Perhaps my scans were running too frequently, perhaps another setting got changed, unsure, but it's not a bandwidth issue (for me).

Look at the facts again, you haven’t transcoded by your own admission, non of the settings you have altered have anything to do with buffering if you aren’t transcoding, you’re playing a 125Mbit REMUX, you state you are connecting the NUC to NAS via gigabit, that has a theoretical 1000Mbit or 125MB/s *each way*. Unless you have done something daft like enabled deep media/intro analysis etc. you will use bugger all IO/CPU to do a library scan and it will take minutes, that leaves the IO on the NAS discs and the connection to the TV.

The way UnRAID works means reading from a pool disc is usually faster than writing to the pool, as it’s only reading from a single disc. 128Mbit is 16MB, no modern drive will struggle to do that sequentially, unless you do something silly like run a parity check while streaming or VM’s/sockets constantly writing direct to the pool (use a cache drive). So assuming you haven’t done any of the above, that leaves the TV and unfortunately multiple people in successive threads (google it) have bemoaned the B7 and later C7 for the 100Mbit port causing exactly the issue you describe. For reference, just because the spec stipulates upto 128Mbit, the encoding is done using VBR and not all REMUX files will ever hit 100Mbit+, it depends on the film and the specific scene. If you have more info that points at something else i’d love to be proved wrong, but based on the information available, it’s not looking likely.