I have a TVS-473. And when I look at the specs, considering the CPU, I read that it could do 2 transcodings simultanious.
I was playing a movie last week and decided to check things on the 673.
To my astonischment was the CPU at 80-90%. Where normal with 1 virtual machine loaded is 3-10%.
When I looked what plex was doing, it appeared to transcode, sound. From AAC3 to AAC.
I tried another movie. And that one was direct playing. Also putting the CPU at 80%.
I used a Nvidia Shield, only for playback. The Plex server was installed on the Qnap.
Everyting is connected via 1 GB Cat 5/5e cables.
Now I wonder, what part of transcoding or directplay I did not understaand.
4.3.4.0435 is the version. I think, that is the latest version.
Plex version: Version 1.5.5.3634 And that is not the latest version, as I do not prefer Spyware on my servers.
HDMI is directly coupled to the TV.
If I do the passtrough on “OFF”, the sound is not disturbed.
CPU is by times 80+ % high and drops than to 10%.
If I put Passthrough on auto, the normal sound is gone, And I only get some load ticking like a drill.
The AMD-based QNAPs don’t have Intel QSV (Quick Sync Video). That’s the biggest difference.
Next, the Linux LibVA doesn’t support everything yet. It’s an Intel project so it’s up to AMD to step up here too.
Lastly, and as seen on Windows, If you get all the stars to align , external GPUs (cards) can work.
Did you double check the math?, 2000 Passmarks / 10 Mbps H.264 video to trancode / active stream.
2 streams of 20 Mbps video being transcoded = 2 * (20/10) * 2000 = 8000 Passmarks for software transcode (when a GPU isn’t detected and enabled)
Thank you for trying to explain it to me.
I can follow the 2000 passmark for 1 stream.
But I cannot follow why you count 2 streams double. Does that have to do with the datastream?
If I translate it all correctly, then 4 streams is 4* (40/10)*2000=32.000?
No wonder I see most plex users have pretty big servers. Where I always thought they where streaming for the whole town.
Not really. Because of the rule that for an HD stream you need a pc with at least 2000 Passmarks.
Where do the second 2000 passmarks come from?
I think I am gonnah learn something.
Correct. 10 Mbps 1080P is fine. As you increase bit rate or the number of streams, the bitrate fluctuations within the video itself, and where the transcode data buffers align (how far ahead of playback need is the player’s buffer), it may or may not play seamlessly.
ChuckPA/Trexx,
What about 4K? Not that I have it, but in case you would like to do that. Would that mean 8*2000 passmark?
As I thought to have been reading that 4K is 80 bitrate?
I just realized I left out a very important piece of information HEVC vs H.264 bitrates. HEVC affords 50% to 64% reduction over the same image in H.264.
Using my example above; 26 Mbps / 0.50 = 52 Mbps (conservatively). Since nothing is free. HEVC requires more computational power. This is the trade-off. Processors can get faster but bandwidth, like Wifi or Gigabit LAN, is a fixed and limited capability. The goal was the obvious “more data in less space (media or transmission)”
Slowly I am coming to the point where I understand, where a lot of Plex users have Dual-Xeons running including a 10GBe network.
Where I was thinking they where serving half of the neighberhood, it is more, serving them selves.
Luckily I have max 2 streams.
Which does not take away that it might give hickups.
If I do not want that, I need a faster CPU.
Thanks for explaining.
Really the biggest impact on Plex Server performance is the Plex Client Devices… If the devices support DirectPlay capability, then the client really is doing the majority of the work, and the Plex server/NAS is just streaming data (i.e. your ISP/LAN connections becomes your bottleneck).
It’s when you have to start transcoding (especially video) that the overhead on the Plex Server really starts to kick in from a CPU perspective.
Here is what you can do, over WiFi, if you prepare your videos up front just enough. What will shake your beliefs is: Synology DS-1813+ (Atom D2700 CPU)
This video was filmed using the Samsung app for those who don’t recognize it
