Unraid NAS struggling to transcode Plex - HP Microserver N54L

[ScottR]

I currently run a HP N54L as an Unraid NAS.

The system specs are:

AMD Turion Neo II 2.2GHz

8 GB RAM

4TB Storage + 2TB parity (3x2TB Seagate Barracuda 7200RPM HDDs)

I run Plex in a docker on the Unraid array.

 

90% of the time Plex will transcode fine, even with multiple 1080p streams, however there are times (usually when I have company) that it buffers and freezes.

 

At first I thought it could be a problem with my chromecast as it usually happens while streaming to that, however checking the Plex logs I can see that it does struggle, transcoding at less than 1.0 (real time).

 

Are there any solutions to easily get around this?  Is there a better CPU I could use, or would an extra 8GB of RAM fix the issue?

 

Thanks,

 

Scott

[alpenwasser]

- snip -

I don't have experience with Plex per se, but transcoding in general is quite CPU-intensive, so if you're going to upgrade, I'd go for the CPU instead of RAM, unless you actually find that your machine does run out of RAM.

I would also try to find out if there's a common denominator for the videos with which it struggles. 1080p is not 1080p after all, bitrates can vary significantly, and in the end it's bitrate (both input and output) more than resolution which matters for transcode speeds, at least in my experience.

But yeah, as a general rule of thumb, if you're transcoding, more CPU == more better. It's not the only thing that matters, but in my experience it's what has the most impact.

[ScottR]

I don't have experience with Plex per se, but transcoding in general is quite CPU-intensive, so if you're going to upgrade, I'd go for the CPU instead of RAM, unless you actually find that your machine does run out of RAM.

I would also try to find out if there's a common denominator for the videos with which it struggles. 1080p is not 1080p after all, bitrates can vary significantly, and in the end it's bitrate (both input and output) more than resolution which matters for transcode speeds, at least in my experience.

But yeah, as a general rule of thumb, if you're transcoding, more CPU == more better. It's not the only thing that matters, but in my experience it's what has the most impact.

 

 

Thanks.

 

I've had a bit of a google and it looks like my processors socket is BGA812.

 

I can't find any more powerful processors that use this socket type.  Is anyone aware of any?  Or would it require a new motherboard?

[Blake]

Thanks.

 

I've had a bit of a google and it looks like my processors socket is BGA812.

 

I can't find any more powerful processors that use this socket type.  Is anyone aware of any?  Or would it require a new motherboard?

I have the same HW setup for my home server (running straight windows server 2012). It is under powered for anything that is CPU intensive (heck having 4x 6TB WD RED in RAID5, I have max writes of ~40MBPS). You need to minimize CPU usage as much as possible. For example I run mine as a File Server (1.0GBPS + Read speeds as it doesn't need to calculate parity), + SQL server for XBMC/KODI. 1GBPS is approx 8x the bandwidth provided by gigabit (bit v byte), and a Full 1080p Bluray rip can easily be streamed across it (your looking at about 10-20MbPS).

 

What you are looking at is on the fly transcoding versus pre-transcoded signals. The ones that have the 5-10fps are doing on the fly transcoding, the ones that are butter smooth and have no issue, are already transcoded and don't need anything done to them (then you go and send something to chromecast which want's a different format to be used and it needs to transcode it). If you really require on the fly transcoding HP no longer make the Gen7 Microserver, so your only going to be able to look at Ebay for replacement mobo/cpu (of which you will find next to nothing that will fit the case). Your other option would be the Gen8, which (if you can find them) has a user replaceable CPU, heck you can even throw a Xeon in them (but you'd have quicksync at that point so you can offload plex transcoding to that).

[braneopbru]

I currently run a HP N54L as an Unraid NAS.

The system specs are:

AMD Turion Neo II 2.2GHz

8 GB RAM

4TB Storage + 2TB parity (3x2TB Seagate Barracuda 7200RPM HDDs)

I run Plex in a docker on the Unraid array.

 

90% of the time Plex will transcode fine, even with multiple 1080p streams, however there are times (usually when I have company) that it buffers and freezes.

 

At first I thought it could be a problem with my chromecast as it usually happens while streaming to that, however checking the Plex logs I can see that it does struggle, transcoding at less than 1.0 (real time).

 

Are there any solutions to easily get around this?  Is there a better CPU I could use, or would an extra 8GB of RAM fix the issue?

 

Thanks,

 

Scott

There is a setting in Plex for the transcode buffer. Plex will run the CPU at full tilt for x many seconds before throttling the CPU down. You might try increasing the transcode buffer to a higher value. possibly 120 -180 seconds vs the default 60. 

 

That CPU is soldered to the motherboard. It can not be upgraded. Plex sugests as a rule of thumb a passmark score of 2000 per 1080 transcoded stream; your CPU has a passmark of 1395, so you're going to have trouble with that. 

 

Adding more RAM probably won't help, unless you're getting close to max usage. But I doubt that you're using any more than 1-2 gigs at any given moment anyway.

[ScottR]

There is a setting in Plex for the transcode buffer. Plex will run the CPU at full tilt for x many seconds before throttling the CPU down. You might try increasing the transcode buffer to a higher value. possibly 120 -180 seconds vs the default 60. 

 

That CPU is soldered to the motherboard. It can not be upgraded. Plex sugests as a rule of thumb a passmark score of 2000 per 1080 transcoded stream; your CPU has a passmark of 1395, so you're going to have trouble with that. 

 

Adding more RAM probably won't help, unless you're getting close to max usage. But I doubt that you're using any more than 1-2 gigs at any given moment anyway.

OK, thanks.

Should I leave transcoder quality set to Automatic, or change to "prefer higher speed encoding"?

[braneopbru]

OK, thanks.

Should I leave transcoder quality set to Automatic, or change to "prefer higher speed encoding"?

I'd leave it set to "higher speed". Plex should do it automatically, but you never know.