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macrumors 68000
Original poster
Dec 6, 2009
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I am posting in the Mini section not because I am necessarily looking to purchase a Mini or that I even know one. However, the next practical and obvious choice to upgrade my HTPC setup brought me here.

I currently use an iMac with Plex. The iMac is set to never sleep (waiting on Time Capsule so I can enable "Wake on Network Access").

Anyway, everything is wireless. The iMac is going to the router which is going to my LG TV with built in Plex.

So far I have gotten away with this setup because I have been streaming relatively non-demanding bitrates.

I am starting to notice some serious stuttering and buffering though within the Plex app for my LG TV. For instance, on "Game of Thrones", the intro stutters the whole way through, but the rest of the show generally plays fine. I have also had some 10GB+ Blurays stream and pause to buffer quite frequently as well.

I just don't understand why my router isn't handling the streams properly? Even if I was getting a realistic throughput of 150Mbps, I am in no way using nearly that for this stream?

Anyway, I am wondering if I just run an ethernet to either my iMac or my TV if it would make an insanely noticeable difference. Or is there anything I can do to improve wireless throughput and speed? Again, I am considering a Mac mini if it is the only way around this.
 
What model is your iMac? If it is older it may be having trouble transcoding the video in real time. Not sure what your level of computer savvy is, but I set up a Linux server to host my plex media library. Just got a core i5 2500 and it has handled any video I've thrown at it. The advantage of doing it this way is that you can just throw a ridiculous amount of hard drives in it compared to using a Mac.

That being said you could do a simple test... If you have an laptop, or a friend with a laptop, just place the laptop near the TV and start a file transfer from your iMac to the laptop. Open up Activity Monitor and keep an eye on the bandwidth. This will tell you if you are getting enough over wifi or if there is some interference that is degrading the performance. If this is the case, you could try changing the channel on your router in case there is interference from other wifi networks. And I'd that doesn't help it could just be your building that is absorbing the signal. Most buildings were designed before anyone thought abou wireless communication and sometimes cause problems.
 
Thanks for the reply. I have 2011 iMac.

The tip about watching the network activity is a good one - I'll try that.

I was indirectly asking a technical question as well - does the size of the file have anything to do with how fast it move across the network (mb/s). Also, how can I determine what throughput I need for any given movie?
 
I was indirectly asking a technical question as well - does the size of the file have anything to do with how fast it move across the network (mb/s). Also, how can I determine what throughput I need for any given movie?

I don't think it matters. Unless you were transfering thousands of little files that sum up to a large size (opposite to a single large-sized file) because files on the receiving file system would have to be created with their "metadata" (inside the hard disk, pointers to their contents and so on), which is why usually for instance, deleting a single 10 GB file is done in a blink, but deleting thousands of files that sum up to 1 GB takes longer.

But in the case of streaming I think it's different as the player of the stream just either uses memory to allocate and output to screen (for instance) or at most a local cache of information.

Regarding the second question, this might help.
 
Change the channel your wifi is running on. Or alternatively, run a [temporary] cable to eliminate the network as the source of the issue.

I think in all likelihood it'll be the wireless.
 
to get true 150Mbs you would have to pay like 270 dollars a month just for internet. that speed is expensive. chances are you have 5/25 (baseline) or 25 upload /30 download. How much internet traffic you have will affect it. also the connection speed you see in windows or under macs utility is not your actual speed.
 
to get true 150Mbs you would have to pay like 270 dollars a month just for internet. that speed is expensive. chances are you have 5/25 (baseline) or 25 upload /30 download. How much internet traffic you have will affect it. also the connection speed you see in windows or under macs utility is not your actual speed.

Over his network, I don't think he's talking about getting 150mbs over the internet?.. but over his wifi.
 
Thanks for the reply. I have 2011 iMac.

The tip about watching the network activity is a good one - I'll try that.

I was indirectly asking a technical question as well - does the size of the file have anything to do with how fast it move across the network (mb/s). Also, how can I determine what throughput I need for any given movie?

On the surface no. Files will move across the network at whatever rate the current bandwidth allows. If you attempt to transfer two files both of their rates will drop.

However you're talking about streaming video, so another question you might ask is, "Will streaming larger video files affect performance?" And the answer is probably. Let's examine a couple examples.

If you stream one video that is 300MB large and 30 minutes long you need to be able to transfer 10 MB per minute. If you then stream a video that is 600 MB and an hour long then you still need to be able to stream 10 MB per minute.

Now if you want to stream a video that is 600 MB and 30 minutes long you will need to be able to transfer 20 MB per minute.

So by large files I assume you mean movies which are typically 1.5-2 hours long. So larger file size typically means larger bit rate.

When you are talking about network speed you typically do so in bitrates. A byte is 8 bits. So the average bitrate of a video file would be to take the file size multiply by 8 and then divide by the length in seconds. Bitrates for movies are typically 10 Mb/s on the higher end, but probably even larger for a direct blurry copy. Yes that's a lower case b on purpose megabits, divide by 8 to get just over 1 MB/s (megabytes per second). This is easily doable on a good wifi n network. If your still having trouble as mentioned earlier changing the channel on your router might work, are ther a lot of other wifi networks in range?
 
When you are talking about network speed you typically do so in bitrates. A byte is 8 bits. So the average bitrate of a video file would be to take the file size multiply by 8 and then divide by the length in seconds. Bitrates for movies are typically 10 Mb/s on the higher end, but probably even larger for a direct blurry copy. Yes that's a lower case b on purpose megabits, divide by 8 to get just over 1 MB/s (megabytes per second). This is easily doable on a good wifi n network. If your still having trouble as mentioned earlier changing the channel on your router might work, are ther a lot of other wifi networks in range?

The file I am trying to stream is only 720P @ an hour long. It is around 3gb. By your logic I need around 50mb to per minute which = .83mb/s = ~6Mbps.

If it only requires 6Mbps then why am I still receiving stutters? I am using N equipment.
 
The file I am trying to stream is only 720P @ an hour long. It is around 3gb. By your logic I need around 50mb to per minute which = .83mb/s = ~6Mbps.

If it only requires 6Mbps then why am I still receiving stutters? I am using N equipment.

Did you try the simple bandwidth test I suggested earlier? Did you get the required bandwidth? If so then it might be suggesting that your TV might not be capable of connecting to the network or decoding he video fast enough. There are many devices that can play video from a plex server, you could try playing the video from another device that is located near the TV. That might give you an idea of it is the network or your TV that is causing the problem.
 
It seems like this issue just started as well and I can't pinpoint the problem.

According to activity monitor, I was getting 3.0mbps upload which is way higher than the .83mbps I needed. The video still stutters and sometimes remains watchable for 5-10 min but goes back to stuttering eventually.

If I put the video on a flash drive, it plays fine.
 
It seems like this issue just started as well and I can't pinpoint the problem.

According to activity monitor, I was getting 3.0mbps upload which is way higher than the .83mbps I needed. The video still stutters and sometimes remains watchable for 5-10 min but goes back to stuttering eventually.

If I put the video on a flash drive, it plays fine.

I know exactly where you are coming from. In fact I have a similar setup (FreeNAS with XBMC on a mini), and I was experiencing the same issues.

Plex is based on XBMC, and there is a thread floating around the XMBC forums explaining why wireless for HD is a big no no. It's mainly because XBMC does not really buffer video. Yes I know it says buffering, and this is all explained much better on the XBMC forums (http://forum.xbmc.org/) by one of the developers. But long story short, wifi is not a continuous stream, and anytime it get's interrupted your video will stutter.

Luckily my home was wired with cat5e for the phone, so I used the spare pair as 100Mbps and converted a few outlets in my home to cat5 (http://www.mavromatic.com/2005/06/how-to-wire-an-ethernet-and-phone-jack-using-a-single-cat5e-cable/).
 
I am posting in the Mini section not because I am necessarily looking to purchase a Mini or that I even know one. However, the next practical and obvious choice to upgrade my HTPC setup brought me here.

I currently use an iMac with Plex. The iMac is set to never sleep (waiting on Time Capsule so I can enable "Wake on Network Access").

Anyway, everything is wireless. The iMac is going to the router which is going to my LG TV with built in Plex.

So far I have gotten away with this setup because I have been streaming relatively non-demanding bitrates.

I am starting to notice some serious stuttering and buffering though within the Plex app for my LG TV. For instance, on "Game of Thrones", the intro stutters the whole way through, but the rest of the show generally plays fine. I have also had some 10GB+ Blurays stream and pause to buffer quite frequently as well.

I just don't understand why my router isn't handling the streams properly? Even if I was getting a realistic throughput of 150Mbps, I am in no way using nearly that for this stream?

Anyway, I am wondering if I just run an ethernet to either my iMac or my TV if it would make an insanely noticeable difference. Or is there anything I can do to improve wireless throughput and speed? Again, I am considering a Mac mini if it is the only way around this.

I am not sure if you have the same problem as I do, sometimes my LG TV while I am watching movies through Apple TV it flashes and makes noise. This gets worse over time, and one day I decided to pull the HDMI plug from Apple TV and re plug it and it stopped.
 
While one would hope the LG TV would actually buffer the video (The AppleTV plex client does) it does sound likely that it is a connectivity problem. Is there anyway you can at least temporarily hardwire the TV?
 
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