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Is standard 100mbps ethernet OK for HD streaming?

NeilF

Well-known Member
If we take say a worse case scenarion? A 30GB moving lasting 2hrs? How much data per second has to be streamed?

30*1024*8=245760mbits total file size

245760/(2*3600)=34mbps transfer required

So worse case scenario, you'd need to get 34mbps from your storage and through your network.


Now, of course, that's an extreme example, so I expect generally it's about half that rate required, so about 15-20mbps?


Are these figures about right? Can a standard 100mbps ethernet network cope happily with these?

And if there's homeplugs in there too?
 
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answer should be yes - no idea on the math but I have been doing it for months.

PC - 100mb wired - A-100 PCH streaming 1080p file 12GB in size.

Over a powerline 200mb hmmm going to be a close one as I dont seem to get much more then 35mb, couldnt say if that would be smooth or not.
 

Uridium

Well-known Member
U sed to run 100mb and it would stream 1080p ok but I did occasionally have some stutters on very high bitrate stuff and ffwd/rwd could be a little hit and miss at time. Saw a big improvment when i moved to Gigabit.
 

NeilF

Well-known Member
U sed to run 100mb and it would stream 1080p ok but I did occasionally have some stutters on very high bitrate stuff and ffwd/rwd could be a little hit and miss at time. Saw a big improvment when i moved to Gigabit.
That would seem to imply that (unfortunately) the storage should be at the media player's end, and not buried away over homeplugs etc etc...? :(
 

TheBlueRaja

Active Member
If we take say a worse case scenarion? A 30GB moving lasting 2hrs? How much data per second has to be streamed?

30*1024*8=245760mbits total file size

245760/(2*3600)=34mbps transfer required

So worse case scenario, you'd need to get 34mbps from your storage and through your network.


Now, of course, that's an extreme example, so I expect generally it's about half that rate required, so about 15-20mbps?


Are these figures about right? Can a standard 100mbps ethernet network cope happily with these?

And if there's homeplugs in there too?
Yes, 100Mbps is more than up to the task even in this scenario...

30 Gig is around 30720Megabytes

Which is 245760 MegaBITS (8*30720)

To transfer this over a network that runs 100mbps (PER SECOND) we take 100 multiply it by 60 for Megabits per minute then multiply by 60 again to get Megabits per hour.

This roughly works out at around 360000Mbph.

So in an hour we can transfer 360000 megabits but we would only need to transfer 245760 as per your worst case scenario.

Therefore given that your film lasts 2 hours (so we in actual fact can theoretically transfer 640000 megabits in that time) we have ample overhead available even if we do take into account TCP-IP overhead and that you'll probably only ever achieve 80 - 90% utilization.

Hope that helps.
 

dwhite

Well-known Member
To transfer this over a network that runs 100mbps (PER SECOND) we take 100 multiply it by 60 for Megabits per minute then multiply by 60 again to get Megabits per hour.
Thats assuming you will actually get 100mbps over the powerline, which is the theoretical maximum and is unlikely to be achieved in a real world situation.

You can do all the calculations, but until you actually test it on your own power distribution, you don't really know.

I think NeliF estimation of 15-35mbps required is probably close, but whether you can achieve that constantly is down to the installation.
 

NeilF

Well-known Member
Thats assuming you will actually get 100mbps over the powerline, which is the theoretical maximum and is unlikely to be achieved in a real world situation.

You can do all the calculations, but until you actually test it on your own power distribution, you don't really know.

I think NeliF estimation of 15-35mbps required is probably close, but whether you can achieve that constantly is down to the installation.
OK... I guess I shove a couple of large test files on my Shuttle and try and watch them...

As pointed out above, also try and FF and REW and see how they behave...
 

TheBlueRaja

Active Member
Thats assuming you will actually get 100mbps over the powerline, which is the theoretical maximum and is unlikely to be achieved in a real world situation.

You can do all the calculations, but until you actually test it on your own power distribution, you don't really know.

I think NeliF estimation of 15-35mbps required is probably close, but whether you can achieve that constantly is down to the installation.
Im talking Ethernet not powerline, i doubt very much Powerline is upto the job, in fact i know its not as i have homeplug.

You'd need the Homeplug AV 200mbps equipment for the job.

Looking at the figures and assuming you actually get 35mbps you'd scrape it home IF you forgot about the TCP/IP overhead and the line was PERFECT.

Thats the reason you need the faster plugs for HD material.
 
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dwhite

Well-known Member
~Sorry My bad read the title wrong thought it was on about powerline/homeplugs

My apologies.

NeilF, you have an xtreamer right, I'm guessing (like the PCH A110) that the ethernet port on it will only support 100Mbps anyway, so thats the most your gonna get, no Gigabit streaming.
 
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NeilF

Well-known Member

charles_b

Active Member
The Problem with 200Mbps Homeplug is the startling fact that the Ethernet port on each of the adaptors is still only 100Mbps.

The aim of the 200 is to ensure that maximum throughput across the Electricity Cables, which once again will depend on the quality and noise on the lines themselves. This will ensure that you get the maximum from the 100 Mbit Ethernet ports

I run on 85Mbps Homeplug currently and I get ~ 50 Mbps.

But you'll only ever get around 65-70% utilisation of the Ethernet port, due to overheads, both physical wiring (Cat5e/6) and ethernet itself, so if you are getting 70Mbps, you are doing extremely well.

The new Belkin Gigabit Homeplug adaptors have both Gigabit Powerline and Gigabit Ethernet, so the potential to achieve greater than 100 Mbps is there!

Of course the best would be Gigabit Router, NAS and Gigabit adaptors in all equipment, but very few peripherals have this
 

Uridium

Well-known Member
The Problem with 200Mbps Homeplug is the startling fact that the Ethernet port on each of the adaptors is still only 100Mbps.

The aim of the 200 is to ensure that maximum throughput across the Electricity Cables, which once again will depend on the quality and noise on the lines themselves. This will ensure that you get the maximum from the 100 Mbit Ethernet ports

I run on 85Mbps Homeplug currently and I get ~ 50 Mbps.

But you'll only ever get around 65-70% utilisation of the Ethernet port, due to overheads, both physical wiring (Cat5e/6) and ethernet itself, so if you are getting 70Mbps, you are doing extremely well.

The new Belkin Gigabit Homeplug adaptors have both Gigabit Powerline and Gigabit Ethernet, so the potential to achieve greater than 100 Mbps is there!

Of course the best would be Gigabit Router, NAS and Gigabit adaptors in all equipment, but very few peripherals have this
Homeplugs were ok for me for a while but wouldn't go back to them. One of the nice things about the PS3 is the gigabit NIC onboard ;)
 

Fotis_Greece

Novice Member
100mbs is OK for most HD streaming. My Raidsonic MP305 can playback with no problems a HD 1080p mkv file encoded at 24Mb/s bitrate, from my Qnap 119 Nas drive.
 

NeilF

Well-known Member
I've got a 15m ethernet cable... So I'll plug the XTreamer straight into the router and see what happens. I suspect it will work fine... So God knows where that leaves me :(

As I said, I bought the homeplugs specifically to connect the XTreamer to the router...
 

NeilF

Well-known Member
Right! Tried the 15m cable and stuttering gone...

Where does this leave me now?
 

DavidT

Well-known Member
I am using Devolo 200mbps AV homeplugs and can stream 720p HD movies with no issues at all to my PlayonHD. I haven't tried 1080p as I dont have a full HD TV so there is no point streaming 1080p movies.

David
 

NeilF

Well-known Member
I am using Devolo 200mbps AV homeplugs and can stream 720p HD movies with no issues at all to my PlayonHD. I haven't tried 1080p as I dont have a full HD TV so there is no point streaming 1080p movies.

David
720p in itself means nothing... It could be a 40mbps file or a 1mbps file...

I might have to send these things back if they're not going to allow me to watch tiny 8gig 720p files :( Maybe a wireless N access point then...
 

DavidT

Well-known Member
A decent quality 720p movie is going to be a least 4GB or 5GB in size. The movies I have are between 5GB and 9GB 720p. I'm surprised the Xtreamer is having problems over the homeplugs, I thought the movies were buffered by the Xtreamer.

David
 

ChrisNic

Active Member
Im not encouraged by this thread, I dont fancy having to run cable through my new house (when I get there!) I was hoping homeplugs would do the trick.

I tried a bluray rip (30gb) over wireless earlier, not quite good enough ;)
 

lmaolmao

Active Member
If we take say a worse case scenarion? A 30GB moving lasting 2hrs? How much data per second has to be streamed?

30*1024*8=245760mbits total file size

245760/(2*3600)=34mbps transfer required

So worse case scenario, you'd need to get 34mbps from your storage and through your network.


Now, of course, that's an extreme example, so I expect generally it's about half that rate required, so about 15-20mbps?


Are these figures about right? Can a standard 100mbps ethernet network cope happily with these?

And if there's homeplugs in there too?
Unfortunately it doesn't quite work like that. movies are encoded in 2-pass variable bitrate, which means that the data transfer rate varies all the time.

your maths is looking at a constant bitrate, something which would look pretty poor.

most movies i've looked at (straight bluray .m2ts rips, no encoding) peak at about 38mbps. with ocassional ones peaking at 54mbps. i have read that some versions of sin city peak at 60mbps. the HBO logo on band of brothers peaks quite high, for example.

What this means is that your movie may typically run at 20mbps, but have parts which jump up.

a 100mbps line is fast enough, wether the player is up to it is entirely different!

Yes, 100Mbps is more than up to the task even in this scenario...

30 Gig is around 30720Megabytes

Which is 245760 MegaBITS (8*30720)

To transfer this over a network that runs 100mbps (PER SECOND) we take 100 multiply it by 60 for Megabits per minute then multiply by 60 again to get Megabits per hour.

This roughly works out at around 360000Mbph.

So in an hour we can transfer 360000 megabits but we would only need to transfer 245760 as per your worst case scenario.

Therefore given that your film lasts 2 hours (so we in actual fact can theoretically transfer 640000 megabits in that time) we have ample overhead available even if we do take into account TCP-IP overhead and that you'll probably only ever achieve 80 - 90% utilization.

Hope that helps.
again, slightly different, we need to have a high instantaneous transfer rate, not a high average.

players dont have very large buffers.
 
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NeilF

Well-known Member
A decent quality 720p movie is going to be a least 4GB or 5GB in size. The movies I have are between 5GB and 9GB 720p. I'm surprised the Xtreamer is having problems over the homeplugs, I thought the movies were buffered by the Xtreamer.

David
I don't think it's the XTreamer... I recon it's the Homeplugs just no being fast enough?
 

jackyK

Novice Member
I don't think it's the XTreamer... I recon it's the Homeplugs just no being fast enough?
On the A-110, the physical limitation for transfers is indeed 100 mbps, but in practice no more than 50 mbps is actually achieved, which I understand should be more than enough for pretty much all purposes.
Network Performance - NMTWiki

I have a pair of cheap 200 mbps Homeplugs at home and have never had any problems streaming 1080p MKVs even with DTS sound or multiple audio tracks. The only extremely rare exception (happened once or twice) I can recall was a scene with some waterfalls or similar which presumably had very high bitrate and where the film slowed down for a few seconds before picking up again.

That was really not much of an inconvenience and for me, Homeplugs have been perfectly fine for streaming HD content. However, I understand that performance can vary depending on the wiring in your home and can sometimes be improved by refitting some plugs, etc. (there is a Homeplug FAQ somewhere on this board with lots of information on this).
 

NeilF

Well-known Member
It's a problem with the XTreamer... Myself and someone else are both experiencing similar problems. The XTreamer appears to be poorhomeplug networks, even though they are 4 or more times the necessary speed.

I've proved this with tests and even playing videos fine over the homeplugs, when the XTreamer stutters.

Someone else has tried different media players, and the only one to show problems over homeplugs is the XTreamer...
 

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