[Solved] Stuttering playback.

[sam_roberts30]

I'm currently running unraid 4.7, a sempron 145, 4gb ram, 5400rpm drives and gig network. I got a bit of stuttering during playback of a bluray iso. Will uping the ram to 8gb or 16gb reduce the chance of stuttering during playback?

[garycase]

Not likely.    Stuttering is FAR more likely to be a network issue.  The exception is if you have a LOT of simultaneous streams -- in which case more RAM may indeed help;  but 4GB should be FAR more than UnRAID needs to provide several streams with no stuttering issues.

 

You indicated you have a Gb network -- are you streaming this over that ... or is there a wireless client involved?

 

One simple test to confirm the network speeds are good:  Copy the BluRay ISO to your PC and watch the rate at which it copies (Win7 or 8 shows this;  with earlier versions of Windows just time it).

 

[Automatic]

Stuttering is FAR more likely to be a network issue.

 

Really depends, I've had files that are so huge in bitrate (Around 2GB for a 10 second clip) that my hard-drive couldn't keep up, I could only watch it when it was located on a SSD.

 

One simple test to confirm the network speeds are good:  Copy the BluRay ISO to your PC and watch the rate at which it copies (Win7 or 8 shows this;  with earlier versions of Windows just time it).

 

I'm going to say that's not the best way, the best way (or I would think) would be with iperf:-

iperf -c 192.168.88.200
------------------------------------------------------------
Client connecting to 192.168.88.200, TCP port 5001
TCP window size: 22.9 KByte (default)
------------------------------------------------------------
[  3] local 192.168.88.251 port 43813 connected with 192.168.88.200 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec  1.05 GBytes   906 Mbits/sec

 

That way it cuts down any sort of hard-drive bottlenecks.

[TheWombat]

I'm currently running unraid 4.7, a sempron 145, 4gb ram, 5400rpm drives and gig network. I got a bit of stuttering during playback of a bluray iso. Will uping the ram to 8gb or 16gb reduce the chance of stuttering during playback?

 

What is your setup?

I assume the blu-ray iso is on unraid

Do you have a Windows HTPC that you are using to view the movie - if so what are the details e.g.

a) are you using Virtual Clone Drive or Daemon Tools Lite to mount the iso and what version?

b) what operating system are you using?

c) are you using ArcSoft Total Media Theatre or to view the movie and if so what version?

d) what graphics card and driver version do you have?

 

I had a similar set up and had no issues with 4gb ram, gigabit network, 5400gb drives for playing 40gb blu-ray ISO images being played on Arcsoft TMT 5.3.1.144 on Windows 7 HTPC.  I use an AMD Radeon 55xx series and Catalyst 11.4 drivers (I found issues with most later drivers hence just stuck with 11.4)

 

If you are using Microsoft Windows as your client then you may also need to adjust a registry setting as by default Windows will throttle non-multimedia (and an ISO is considered non-multimedia). You can Google to get more details however in summary:

 

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Multimedia\SystemProfile\]

Set "NetworkThrottlingIndex"="FFFFFFFF"

 

The hardware and ram you currently have are fine to play BluRay isos. The issue is elsewhere.

 

I am now moving from ISO images to MKV as it makes life much easier if you are using Plex.

 

TheWombat

[garycase]

If the bitrate is as intense as Automatic indicated it can be, then I suppose it could be related to the disk access -- but I doubt it.    Copy the file to your PC, and try playing it locally -- if that also has stuttering issues, then it may in fact be a sustained data rate issue with the hard drive !!

[sam_roberts30]

I know the network isn't an issue. I'm an electrician and do ALOT of data centre cabling. The network is all screened cat6a. The network map goes unraid -> HP Pro Curve switch -> media player. When I verfied the network using a fluke tester I am get consistent results of 104mbps.

 

The media player is a DF Solutions Base media server. It's a high end home cinema source that runs its own proprietary OS which takes care of all the playback and the hardware is all custom too, sorry not much help on that front.

 

I have quite a few 3d bluray iso's and never had a problem. The stuttering happened first on the bluray "9" and again last night on "up". Now this got me thinking, these films a really quite high in bit rate at times so could it be that the hard drives in the array aren't fast enough to keep up? I.E need 7200 rather than 5400 drives for blue rays? To be honest I have been thinking of changing out the desktop drives with enterprise drives anyway so it might be worth going with the faster drives if that could be a cause.

 

 

[garycase]

I presume you mean 104 megaBYTES --- not megaBITS -- is that right?

 

If that's the case, I certainly agree the network's not the issue, as long as you're using the same cables to test as you have connected to the server.

 

But it's difficult to believe that a modern drive can't sustain a data rate sufficient for BluRay.  A modern high-density drive can easily exceed 100MB/s on all but the innermost cylinders => and the HIGHEST bit rate shown in Cinema Squid's list of bit-rates for various movies is 40mb/s -- about 5MB/s or less than 5% of what a typical hard disk can deliver.

 

Before attributing the stuttering to UnRAID, I'd definitely copy your rip to a PC and play it from there => both locally (on the PC) and across your network.    This will not only help isolate WHERE the problem might be occurring ... but also confirm that you have a good rip [i've seen rips of some movies that stutter simply due to a bad rip].

 

[garycase]

... just confirmed that in fact the maximum BluRay data rate allowed per the BluRay specification is 54mb/s -- or about 7mB/s.

 

ANY modern disk can easily sustain that data rate -- in fact it should be sustainable for 2-3 simultaneous streams, even factoring in the disk thrashing of multiple streams.    I wouldn't be surprised to see stuttering with a wireless connection;  but certainly wouldn't expect it with a wired network.

 

Since you're convinced this isn't due to the network topology or cabling, then you simply need to do a bit of testing to isolate what's happening.  But with regards to your questions in this thread:  No, I don't think bumping UnRAID to 8GB will matter;  and No, I don't think moving to 7200rpm drives will help either.

 

What MAY help is changing the drives to A/V drives ... just in case this issue is due to recalibration delays.  A/V drives are designed to significantly reduce the impact of this.

 

[PeterB]

I presume you mean 104 megaBYTES --- not megaBITS -- is that right?

 

... and here I was trying to work out how long file transfers would take at 104 millibits/second!

[sam_roberts30]

Yes thats right, My apologies for the typo.

 

I think I may have found the problem. The player installed new firmware on Friday. I found an email in my junk folder saying the update was not successful and requires a system restore.

 

I am going to watch 9 again and see if the stuttering happens again tonight.

 

Thanks for your help, I'll keep you posted. Thanks again.

[garycase]

Did the restore resolve the problem??