4K Streaming Speed Issues... where is the bottleneck?

General Discussions
1

Howdy Plexers!

I’ve been a happy Plex Pass member for a bit now, and I’m starting to move into ripping my 4K UHD discs, and I’m experiencing the dreaded (but anticipated) slow loading, buffering and other issues. I’m a tremendous troubleshooter on these sorts of situations, but this one is a head scratcher. I was hoping to describe my setup, along with my use cases and see if anyone could shed light on my challenges. Thanks in advance.

Specs
My Plex server is local on a G-Tech 8TB drive, connected to a 2013 Mac Pro via USB 3.
I use Plex through these apps: 4K Apple TV, Sony XBR75X850E using Android TV, LG OLED65B7A using WebOS
All devices above are hard wired via Cat6 Ethernet. The only difference is my LG TV has a 30 ft Ethernet run, Sony about 80 ft.

4K Streaming
It appears the AppleTV app still hasn’t been updated to support 4K streaming, so unless I’m watching an HD BluRay (which I do a lot of) I won’t attempt to use the Apple TV 4k. That said, I rarely (if ever) experience buffer delays or issues with an HD signal or lower. It’s almost always instant-on without interruption.

My LG TV WebOS app seems to be the best I use. It handles most audio codecs (except DTS 5.1, I think, which is odd) without an issue and it uses the Rec2020 space and delivers 4k UHD streams in great quality. Buffering is rare.

My Sony TV with Android TV app seems to have audio figured out up to 7.1 (which my speaker array cannot make use of anyway) but I have a tremendous amount of “slow connection” issues (remember the TV is hard wired) on the same files my LG TV seems to play just fine and without really any lag. I notice the Sony is using “Direct Play” because that pops up on the screen and I experience horrible slow down issues when it tries to convert the audio on playback. My LG doesn’t tell me how it is playing back via on screen menu, but both are always set to "original quality"

The Troubleshooting
I figured the bottleneck was my slower MacPro from 2013 (or the drive via USB 3). I did another server hooked up to a faster drive and connected via USB-C to my MacBook Pro (late 2016) maxed out with 32gigs of Ram. I thought for sure this was the bottleneck, but I had the same 4k streaming issues. Smooth-is playback on the LG and stuttering and very interrupted on the Sony TV.

That got me to thinking my computer wasn’t actually doing the processing. I don’t know much about these TV’s, but maybe one (the LG) has a better processing chip in it than the Sony and some of the heavy lifting is being transferred to the TV itself. I’m not sure how these apps are written or how these are supposed to work.

I also tried the Cloud Server. It was a total non-starter. I’m using Dropbox and it took absolutely forever to even load HD content (like 5 or 6 minutes) and to get something back from being paused etc. was a bit of a mess… forget about trying to navigate or scrub to a specific scene.

So this brings me to my ask.

What am I doing wrong here? I was thinking about buying a new iMac so it could process a bit faster, but maybe my bottleneck is where the files live and the drive read speed. I was thinking about moving TV’s around if the processing stuff happens in the TV itself and that entry level Sony 75 just doesn’t have the juice needed to get me where I want to be.

Does anyone have a similar experience with a resolve? If I was to build a moderately priced rig for Plex only, what is the best device to use?

Any help or suggestion here is helpful. Maybe the Apple TV app (if it is ever updated) will solve everything?

Best

Marc

2

I am happy to try something else here as a testing device. Any suggestions on something to provide more clarity to my situation? Thanks again.

3

Just spitballing, but I think you’re most likely correct about the TVs being the difference. Not knowing if you are getting direct play or a transcode is your missing piece of data. You’ll need to determine whether Plex is transcoding when playing back to either device. If you log into the Plex web client on a computer while you’re playing one of the videos in question on each TV, go to Status -> Now Playing, it will tell you if the stream is direct play or if there’s a transcode happening.

From there you should be able to determine where the bottleneck is. If both TVs are playing back the same way (direct play or transcode), and the problem is only happening on the Sony, then it’s almost certainly at the Sony TV end. But if the Sony is getting a transcode and not the LG (for whatever reason), your PMS is likely the bottleneck. It could certainly be something more complicated, but this is where to start and it’s quick and easy to check all this.

Adding your smartphone to the mix as a testing client would give you a valuable third datapoint as well.

4

Your bottleneck must be the client. You should be set up to Direct Play as you certainly don’t want to be doing any transcoding & don’t need to with your setup. The load on the Mac Pro will be trivial as it is effectively just acting as a file server & your wired network can handle multiple 4K UHD streams.

I don’t have an AppleTV 4K but have seen several users sing the praises of the MrMC app available for a modest price from the App Store. It’s basically Kodi with all the naughty addons removed & a Plex client (among others) that looks a lot like the old Plex Home Theatre client. It Direct Plays everything including 4K HDR. I use MrMC on my Amazon Fire TV 4K & it’s great with a much nicer UI than the awful Android TV UI that the Plex client was given last year.

5

@nigelpb Thanks for the tip. I tried the MrMC today, and it doesn’t work. I’m getting major buffering issues, but worse, it displays the 4k streams in Rec709 color space (very flat color). Somehow (and I don’t really understand this all that much) the Plex apps for both WebOs (LG) and AndroidTV (Sony) are interpreting the same files in the Rec 2020 color space because they look right. I’m wondering if it is a limitation of the Apple TV… like they only output in Rec 709 and that is the issue there.

Either way, I can’t seem to get a smooth stream unless it’s 100% Direct Play. Is there a way to force DirectPlay?

6

@marcdamour said:
@nigelpb Thanks for the tip. I tried the MrMC today, and it doesn’t work. I’m getting major buffering issues, but worse, it displays the 4k streams in Rec709 color space (very flat color). Somehow (and I don’t really understand this all that much) the Plex apps for both WebOs (LG) and AndroidTV (Sony) are interpreting the same files in the Rec 2020 color space because they look right. I’m wondering if it is a limitation of the Apple TV… like they only output in Rec 709 and that is the issue there.

Either way, I can’t seem to get a smooth stream unless it’s 100% Direct Play. Is there a way to force DirectPlay?

Plex app, mrmc and infuse all direct stream/play 4K HDR MKV Remux’s for me on my Apple TV 4K, maybe update to latest Plex media server or turn on deep colour/enhanced on your tv. Btw if you direct play you don’t need a powerful rig, my pc is 7 years old and slow as anything but I can still play everything locally.

7

@Nik3sh said:

@marcdamour said:
@nigelpb Thanks for the tip. I tried the MrMC today, and it doesn’t work. I’m getting major buffering issues, but worse, it displays the 4k streams in Rec709 color space (very flat color). Somehow (and I don’t really understand this all that much) the Plex apps for both WebOs (LG) and AndroidTV (Sony) are interpreting the same files in the Rec 2020 color space because they look right. I’m wondering if it is a limitation of the Apple TV… like they only output in Rec 709 and that is the issue there.

Either way, I can’t seem to get a smooth stream unless it’s 100% Direct Play. Is there a way to force DirectPlay?

Plex app, mrmc and infuse all direct stream/play 4K HDR MKV Remux’s for me on my Apple TV 4K.

Yep for me too although the native Apple TV app transcodes with embedded subs.
Personally I’m leaning towards infuse for my 4K remuxes rather than MrMC.

8

@Nik3sh thanks for the response. I honestly don’t think it is a color setting on my TV… here’s why. If I watch a UHD 4K MKV through the Plex app for WebOS or AndroidTV, the color looks perfect. It stutters a bit when it isn’t direct playing (I’ve narrowed it down to the audio codecs causing the transcoding problems) but it looks perfect.

If I take the exact same MKV and use the exact same TV, only difference is using Apple TV 4K with Plex or MrMc, the color is significantly different. Maybe it is a color space setting in the Apple TV (not the actual TV). I’ll look into that today. Thanks again for everyone’s help. I appreciate it.

9

@marcdamour said:
@Nik3sh thanks for the response. I honestly don’t think it is a color setting on my TV… here’s why. If I watch a UHD 4K MKV through the Plex app for WebOS or AndroidTV, the color looks perfect. It stutters a bit when it isn’t direct playing (I’ve narrowed it down to the audio codecs causing the transcoding problems) but it looks perfect.

If I take the exact same MKV and use the exact same TV, only difference is using Apple TV 4K with Plex or MrMc, the color is significantly different. Maybe it is a color space setting in the Apple TV (not the actual TV). I’ll look into that today. Thanks again for everyone’s help. I appreciate it.

Is Your 4K LG TV deep colour setting to ON for the right hdmi? in tv settings, its only for hdmi devices to enable hdr, webOS is integrated and doesn’t use hdmi so no setting to change, that’s why you get the right colour space.

Also make sure you set your Apple TV 4K to 4K SDR 60fps, chroma 420, match frame rate and dynamic range ON. That’s whats mine on. So when you watch anything hdr it will switch from SDR to HDR automatically.

In addition if you have 4K Netflix/Amazon test if that works on your Apple TV.

Other than that check your Ethernet cable are not faulty. That’s all I can think of, good luck.

10

@Nik3sh I’m embarrassed to say the match color settings function on my Apple TV wasn’t set properly, so I was getting that flat color. It’s set now and I’m able to pass through the appropriate color on the Apple TV. Thanks for taking time with me on this.