Steam streaming over 10Gb fiber LAN.

[Construct]

Im curious to see how this runs over higher bandwidth lower latency medium like 10Gbe fiber in a LAN. I know this is not common place yet but eventually it will trickle down to home users.

[Marble]

Streaming video from one PC to another wouldn't necessarily require any HDD activity at all. It would more likely follow VRAM > RAM > Network> Other PC RAM > VRAM > Display

[El Botijo]

I do think we are mixing stuff together. HDD is a limiting factor if you want to transfer data from the hard disk. However, I thought we were discussing about humoungous data that is created on the fly: audio and video from a video game. Let me get a table of different needed bitrates.

• HDMI uncompressed audio video 1080p@60Hz, 8bit/channel, total bitrate = 4.5 Gbps
  
• HDMI uncompressed audio video 720p@60Hz, 8bit/channel, total bitrate = 2.25 Gbps
  
• NVidia Shield required min WiFi throughput for 720p videogame streaming, compressed video = 0.6 Gbps
  
• Bluray compressed audio video, max allowed bitrate = 0.05 Gbps
  
• Online HD video streaming, recommended download capacitiy = 0.01 Gbps
  
• DVD compressed audio video, max allowed bitrate = 0.009 Gbps

Please note that WiFi throughput is fairly variable on real life, so NVidia might be asking for a higher than needed bandwidth. I do not know what the actual min limit is.
Wired Ethernet connections are 0.01Gbps, 0.1Gbps, 1Gbps.

Hoping that I made my point that bandwidth might be not too important if compressed video is used, latency could be the next problem. Let me give you another table:

• Polling rate for gaming keyboards and mice (yes, the computer is tasked to poll a mouse and keyboard because they do not generate interrupts like old PS/2 interfaces) = approx. 1000Hz, or 1ms (not necessarely the update rate on a video game)
  
• Calculation rate for typical 60Hz locked video game = 17 ms
  
• Calculation rate for typical 30Hz locked video game = 33 ms
  
• Calculation rate for some specific game like Forza 4 on Xbox 360 = 3 ms

So I understand people want to lower latency, but anything lower than 1ms is going to be overkill in my book. UDP/IP cannot be relied upon always giving the same roundtrip time (IP is after all collision aware).

[Martelol]

引用自 El Botijo：

I

• NVidia Shield required min WiFi throughput for 720p videogame streaming, compressed video = 0.6 Gbps

600mbit for shield streaming? ;)

But yes, output will almost certainly be compressed. We obviously don't know what resolutions/framerates will be available, but given the horsepower needed to encode HD video (especially while running the game simultaneously), my bet is on 720p/30. I almost wouldn't be surprised if it uses MPEG2 rather than h.264 just to ease encoding requirements since it's intended to be used over LAN. I'd be surprised if steam's streaming feature uses over 50mbit.

[Xander]

"NVIDIA uses the H.264 encoder built into GeForce GTX 650 or higher desktop GPUs along with special streaming software integrated into GeForce experience to stream games from the PC to SHIELD over the user's home Wi-fi network with ultra-low latency." (http://shield.nvidia.com/faq/)

There is no need for any HDD activity, that would be ridiculous, and the data is encoded within the GPU and not CPU, I don't know much high the latency really is but this is till the best solution to stream the content, right from the GPU, get the compresses images and send the over the network.. most likely the bottleneck will be the TV to decode the data and display it.. :D

Also NVIDIA ShadowPlay requires at least a GTX 600 series GPU, I don't think Steam would rely on that because I don't think most uses own a graphics cars like that yet.

[Zaf]

引用自 Xander：

I don't think most uses own a graphics cars like that yet.

Heeey.... I want a Graphics Car!!! ( ;) )

[Dieter]

引用自 Graham：

You are missing the point of In-Home Streaming.... The Streaming doesnt happen over the internet it takes place between 2 computers in your home. Thus it does not matter what the speed of your ISP.

What? I believe he is saying 10Gb LAN, he did not mention anything about his ISP.

[SFC Foster]

引用自 Construct：

引用自 ShadowCVL：

Unfortunately all that difference in latency would mean precisely nothing, PCI busses wont be able to process the data coming in at 10GBe, unless you are running on a server... but that would be noise prohibitive.

In the home you will have higher latency in the TVs processing than in the network.

Lucky for me i do have a server and almost no periferel card uses PCI anymore almost everything has transitioned to PCI-E which only requires a PCI-E 1.0 4x connection to provide enough bandwidth to accomodate a 10Gbe adapter. I already have the hardware and am looking forward to testing it out with steamOS.

"Beta participants will be randomly selected from members of this group", these types of posts will not draw attention to you. The information is interesting but not useful. Please keep that in mind in future posts.

[Construct]

引用自 SFC Foster：

引用自 Construct：

Lucky for me i do have a server and almost no periferel card uses PCI anymore almost everything has transitioned to PCI-E which only requires a PCI-E 1.0 4x connection to provide enough bandwidth to accomodate a 10Gbe adapter. I already have the hardware and am looking forward to testing it out with steamOS.

"Beta participants will be randomly selected from members of this group", these types of posts will not draw attention to you. The information is interesting but not useful. Please keep that in mind in future posts.

Or im just intrested in what can be done with the hardware i have.

[Yip Yip]

But how would you direct-connect via network cable? Are there 10GBit PCIe network cards yet?
Also, how to connect the fiber to your PC / the Steambox afterwards? Via Cat7 cable? Then you would have the bottleneck via copper cable again.
How do you plan on wiring that up? :P

[coruun]

Infiniband has a latency <2 microseconds

[Zaf]

引用自 Kyshu：

But how would you direct-connect via network cable? Are there 10GBit PCIe network cards yet?
Also, how to connect the fiber to your PC / the Steambox afterwards? Via Cat7 cable? Then you would have the bottleneck via copper cable again.
How do you plan on wiring that up? :P

10gbit/s LAN can be run using a pretty cheap Network card these days (a few hundred bucks). All you need is a high grade LAN Cable and two computers with a PCI-E Slot. You then connect them "crossover" because 10gbit/s switches/routers are not affordable yet.

[Marko]

How about uncompressed streaming. No codec. RAW. Delay would be even lower. Certainly < 10ms.
Bitrate fits 10Gb/s perfectly. 1920 x 1080 x 60Hz = 3.2Gb/s

1. Better video quality
2. Lower Delay
3. Less coding needed, no codec, just copy paste.
4. Less hardware resources needed (cpu or gpu do not need to compress)
5. Less hardware resources needed (cpu or gpu do not need to decompress)