How does Plex work (for dummies)


I am a huge fan of Plex and use it a lot. We have a ton of our movies on my notebook where my plex server software runs and I typically am casting it to one of our TVs connected via a Chromecast 2.

As I was looking at laptop options and moving a lot of data potentiall to an external HDD, it occurred to me that I don't really understand how Plex "works" when streaming it to, say, my Chromecast. I know I have a media folder on my laptop, that the Plex software somehow sends it to the Chromecast. But I'm not entirely sure of the mechanism. Is it using the wireless connection of my laptop to upload the media file I'm casting to the Chromecast? In which case, speed of access to the file (i.e. where the file is on an SSD on my laptop or an external HDD) doesn't matter? Or does it? I assume the upload speed of my internet provider is the bottleneck when casting from the Plex media on my laptop to the Chromecast? Vs. my D/L internet speeds?

And somehow when I use the Plex app on my iphone, is it simply sending commands to my laptop and the Plex software on there?


Media file on disk ----disk speed—> plex media server ----network speed----> plex client.

Disk speeds are generally much faster than network speeds.

Streaming inside your house does not go over the internet. If you stream to a remote Plex client outside your house, it will be constrained by your upload speeds to the internet.

Yes, the plex client on your phone connects to your laptop.


Don’t forget that on something like the Chromecast 2 there is probably a fair chance your media will get transcoded and the transcode delay can be longer than network and disk lagging if your CPU is weak.


Oh man, I was ready to come in here and explain how the economy of EVE Online worked…


Indeed, but he didn’t ask about that. :)


Streaming inside my house does not go over the internet. OK - how does it get from my computer drive to the Chromecast?


Yeah, I’ve dug through a number of threads on how to tweak Plex in order to avoid transcoding or avoid it being a bottleneck. Note: reading a bunch of threads does not = figured it out. ;)


Over wifi.


Oh, OK. Kinda tired and slow tonight. I’m still not 100% clear on how the Chromecast finds the Plex server or vice versa but I can probably figure that out after a good night’s sleep (traveling right now and the airports/rental cars/hotels have numbed the brain.)


They’re on the same local network. Plex runs discovery on the local network to find any plex media servers.


The Plex server process running reads your media from disk and calculates a library. It then listens on the network (acting as a server process) for clients to connect and request library listings. Clients can be other PCs running plex software, devices like phones, or even dedicated media players like Roku or Chromecast. The client devices will either scan the local network to see if a Plex server process answers, or else use your account info to look up where your media server is running. Once they have contacted the server they will request library info, which is how they can show the lists of media available to play. Once you pick a video to watch, then the client requests that the plex server streams it to the client. So the client makes a network connection directly to the Plex server process which reads the file off disk, possibly transcodes (reformats) it as needed, and then sends it across the network for the client to display. This is basically exactly how any streaming media service (such as Netflix) works, but in this case instead of a server out on the internet the server is located on whatever PC/laptop you installed the Plex Media Server software on.


Would Plex, through a Roku, read a dvd in my computer’s tray? Or is it only for movie files? Or folder related?


I’m not going to say there isn’t a plugin that would let you do that, but it’s not built for it all.


You would need to rip the DVD to disk first, which is very easy and quick to do these days.


On a somewhat related topic, does anyone know a convenient way to mirror a desktop PC screen to the Roku without using Miracast? It seems bafflingly hard to do. For some reason there doesn’t seem to be any such thing as a Miracast transmitter dongle, and my graphics card doesn’t support it.


It supposedly works with the built-in windows 8 and 10 mirroring tech. In win10, select “connect” from the action center quick buttons.


Yeah, but only if your PC supports Miracast. Desktops by and large don’t unless you have a Maxwell GPU (and a compatible wifi adapter, which I think I have).

I’ve tried the linked method many times. It recognises the Roku, but steadfastly refuses to do anything when you try to connect.


So there was an update the Plex app on Xbox a week or two ago. Has anyone here used it? It’s really tough to navigate now.

On the old App, you chose the server at the top level, and then you could switch between Movies, TV, etc. And you could browse, and that would take you to an alphabetical listing of all the movies, or all the TV shows, etc.

In the new interface, you choose Home, Movies, TV, Music, Pictures at the top level, and THEN you chose the server under those categories, and then it gives you the choice of categories like Recently Released, Recently added.

But where is Browse? Is that gone? Where do you go to see an alphabetical listing now? Where do you see other categories anymore, like “Top movies with Tom Cruise”, or whatever categories that used to show up in the old Plex app?

And I can’t use voice commands anymore to navigate the interface, or even to Pause and Play anymore. It’s just a downgrade in interface in every way.

But I’m sure I must be missing at least some part of this stupid new interface. There has to be a way to browse Movies and TV shows alphabetically that I’m missing.


I tried Plex a couple of years ago, did the one-month Pass to try it out, and ended up not continuing largely because it didn’t have a good interface with my MythTV DVR. I see now that Plex has added their own DVR system. Anyone used it? My current setup of Kodi as front-end to MythTV is workable, but far from perfect. If Plex’s DVR solution is pretty good, it might be worth a switch.


Wow, I haven’t used MythTV in well over a decade. I switched to Plex->Kodi recently because they now have a plugin that uses the Plex database inside Kodi which allows direct play - no transcoding.

Anyways I tried out the PVR feature a tiny bit. It was by far the easiest PVR I have ever set up, and I think I have setup most of them at one time or another. It just worked, even with the original HD Home Run. I told it to record a show and it did.

I don’t have any good in depth experience or long term use with it, since the only thing I think my wife uses it for is the Oscars or other award shows. We will be depending on it for the Olympics but yeah, a few times a year isn’t much in the way of experience. So far so good though.

Me too. If I wasn’t using the kodi interface I would have switched again by now.