Streaming Speed: 100Mbps/Gigabit?

[NuklearNik]

There seems to be quite a bit of info around on the impact of wireless network performance on watching pleasure for streaming video. What I haven't uncovered is similar information on the importance/relevance of gigabit over 100Mbps wired media streaming. FWIW I'm of the school where main vidoe streaming is to one room in the house, where the TV and surround processor live. So the primary use of media streaming will be wired.

Put simply: Is 100Mbps adequate for good quality video streaming, from a NAS predominantly rather than direct from the web, or should I really be making sure I get devices that are gigabit capable? I assume that the move to gigabit is hardware not firmware driven.

[Johnnie]

As far as I'm aware the maximum data rate for HD is about 25mbps, so I would have thought a wired connection capable of 100mbps should be fine.

[NuklearNik]

Thanks for that Johnnie.

So what happens when your network doesn't achieve the required 25Mbps? Performance testing on smallnetbuilder.com suggests that on a good day a 100Mbps NAS might deliver 10Mbps - unless I'm misreading it, which is always possible. And to get up to 25Mbps performance you actually need to use a Gigabit capable NAS.

Do devices like the EVA8000 have inbuilt RAM for buffering the stream?

[NuklearNik]

Just found this on the BBC website. Thought it might be interesting.

http://www.bbc.co.uk/commissioning/p...ery_campus.pdf

[scooby_doo]

If you're starting off from scratch then it would make sense to buy gigabit equipment purely from a futureproof point of view.

The EVA8000 has a 100Mbps "card" so 100Mbps switches etc will work fine. People have reported success using HomePlug devices but make sure you get the higher speed ones if you're going down that route.

For info, the EVA8000 does uses an internal buffer although with a poor connection speed you are still going to get stuttering obviously.

[scooby_doo]

Originally Posted by NuklearNik

Thanks for that Johnnie.

So what happens when your network doesn't achieve the required 25Mbps? Performance testing on smallnetbuilder.com suggests that on a good day a 100Mbps NAS might deliver 10Mbps - unless I'm misreading it, which is always possible. And to get up to 25Mbps performance you actually need to use a Gigabit capable NAS.

Do devices like the EVA8000 have inbuilt RAM for buffering the stream?

DVDs generally are around 6-7Mbps. It's the HD stuff which uses a lot more.

[NuklearNik]

I was definitely going to go for a gigabit capable NAS. (Just need to change my router) If I can get a decent gigabit capable media streamer then that would also seem sensible, from a future proofing perspective, but not essential from a performance perspective at this stage (well I only have a 25" Trinitron that is going strong). Netgear weren't able to give any clues as to whether they were going to include gigabit in their next generation of media streamer.

[scooby_doo]

Originally Posted by NuklearNik

I was definitely going to go for a gigabit capable NAS. (Just need to change my router) If I can get a decent gigabit capable media streamer then that would also seem sensible, from a future proofing perspective, but not essential from a performance perspective at this stage (well I only have a 25" Trinitron that is going strong). Netgear weren't able to give any clues as to whether they were going to include gigabit in their next generation of media streamer.

No need to swap the router out, just get yourself a gigabit switch and plug it into one of the ports and then plug all your "gigabit stuff" into the switch. I use this sort and they do the job well.

Re the gigabit NAS devices, MOST of them are not capable of running at gigabit speeds despite their network card spec suggesting otherwise

In a couple of years they'll be bringing out 4TB drives so you'll be able to store a decent amount of HD stuff then. What I'm saying is don't buy a bunch of 1TB drives for future needs now because you might be replacing them by the 4TB ones when they come out.

[chris57]

The latest media streamers have the Sigma EM8634/5 chipset which has only 10/100 mbs spec. So having a gigabit network would give zero benefit.

From a transfer point of view the speeds for the popcorn are:-
SMB: ~19Mbps
NFS: ~33Mbps
HTTP: ~42Mbps (same clip peaks at 47Mbps)
USB HDD: ~42Mbps
USB DVDROM (8x): ~42Mbps
Internal HDD: ~42Mbps

So current 1080p HD stuff is peaking well below the 100mb limit. Most HD releases are about 5-8mb/s.

[scooby_doo]

Originally Posted by chris57

So having a gigabit network would give zero benefit.

Perhaps not for a single stream but once you add a few streams and you also want to move large files around your network at the same time then you'll come unstuck if you kit your network out with 100Mbps switches

I started off in the "one stream" school but once I'd discovered how cool they were I decided to buy a few more

If you're starting off with nothing then you'd be wise to plump for gigabit kit to at least give you a bit of headroom for the future.

[ianh64]

To Add to what scooby_doo says, you are not going to get the benefit from gigabit for a single point to point connection - even 100mbs is far in excess of hd data rates. Where gigibit benefits is where there is high levels of traffic on the network as a whole. Gigibit gives the *whole* network breathing space.

I run a gigibit backbone between switches, but (apart from my NAS boxes which are a mix of 1x100mbs and 2xgigabit), do not run any gigibit NIC's in any pc's. There is simply no benefit to me as the point to point speed is ample fast enough. However, I can run a large format printer, continuous backup/shadow jobs, web, email, music streaming simultaneously with bandwidth to spare whereas with a 100mbs backbone, even though I was still within the 100mbs limits (old switch had network utilisation lights), the additional cost of gigabit swithces was money worth spending, if only for me not to worry about breaking any network capacity limits in the future.

As for the router - forget its 100mbs. Assuming its for internet / wireless access, you are not going to break any limits if you hang everything off a switch sitting infront of it - practical limits are far in excess of theoretical limits. Its much cheaper adding a gigabit switch to the router than upgrading the router on its own. My router has two connections - one to the internet, the other to the switch.

One other benefit is that gigabit may have decreased latency on the network. But there is no benefit in being able to accelerate from 100mph to 150mph in 4 seconds if the speed limit is 70mph and the traffic is moving at 30mph.