In Home Game Streaming Latency Test with High Speed Camera
Linus Tech Tips
·Linus Tech Tips
·2014-05-07
·
1,757 words · ~8 min read
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The Cooler Master glacer 240l CPU Cooler delivers the convenience of an
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all-in-one and the performance of a custom water cooler click now to learn
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more latency or lag is the delay between
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an action and the resulting reaction such as in gaming the pressing of a
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button on a controller and the corresponding animation of a character
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on the screen this latency is an enemy of game it makes controls feel less
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responsive and makes it more difficult to among other things time jumps and
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land head shot there are many smaller contributors that make up the total
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latency in the example I just gave ranging from ones small enough to not
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matter such as the delay between pressing a button on your wired keyboard
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and that action being registered by your computer all the way up to image
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processing delays as high as 68
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milliseconds or 3 to four frames of action on a 60 HZ TV today's
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investigation is not a detailed look into the contribution of every single
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one of these leg factors but rather a look at the current state of local game
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streaming technology and whether it's a feasible alternative to plugging
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directly into a PC or game console now
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when I say local game streaming I am not referring to subscription-based cloud
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services like on live that's internet game streaming and has a whole different
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set of challenges because it relies on your internet connection that means
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latency is higher and beyond your control and it also means that like
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Netflix it will use your monthly bandwidth quota if your internet service
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provider has one local game streaming by contrast uses only your own networking
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equipment which can be as cheap or as fancy as you want does not require
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subscription since your games belong to you already and does not use your
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internet connection because both the game serving PC and the client PC or
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device are within your own network so
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here's our setup our streaming computer for all the tests is using a core i7
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3770k CPU with 8 gigs of RAM and a GTX 780ti it's a very high-end machine but
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in order to reduce the variables in our test it was important to use a gaming
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computer that is easily capable of powering these inhome streaming
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solutions for networking we're using an ASUS rtn 66u which is the best consumer
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grade router that I've personally used for game stream and of course uh it has
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gigabit connectivity for our wired examples for our clients we're using a
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Steam OS machine as well as an Invidia Shield to show off those two different
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streaming Solutions so to get started we're going to plug both a CRT Monitor
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and an ASUS pb278q into a PC in cloned
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display mode for a local gaming session we're using Counterstrike sources in
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game Benchmark to simulate our local gaming session because it's really quick
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to launch and it has an explosion that changes the color of the whole frame
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very suddenly and predictably we were able to consistently measure a 10 to 11
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frame difference when filming at 480
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frames per second between the first bright flash of fire on the CRT and the
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first appearance of it on the LCD that gives us about a 22 millisecond delay
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this methodology unfortunately doesn't give us the exact input leg of the
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monitor but since most people won't notice the
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difference between a CRT and an LCD it does allow us to make relative
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comparisons between the contenders while giving us some context for the following
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numbers first up we're going to test
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steam's inhome streaming you can find more details about inhome streaming in
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the link in the video description and to do that we're going to take our LCD and
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run it off of our steam machine a normal PC that is connected via a wired Gab
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Ethernet connection to the same network as our gaming PC the gaming PC keeps the
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CRT so that we can measure the additional delay that is caused by the
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h264 video encoding being done by the server PC the network transfer and then
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the decoding being done by the client PC it looks like it adds about 74
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milliseconds compared to a CRT monitor which is about equivalent to seeing your
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game with a 4 and 1/2 frame delay on a
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60 HZ monitor not bad when you consider that there are TVs that can add as much
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as 68 milliseconds or about 3 to 4
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frames but you also need to remember guys a leggy display will further
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increase the perceived latency so while it's playable in this situation there's
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still a lot of room for improvement and one to two frames would be ideal just in
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case you hook it up to one of those extremely laggy TVs in scenario 2 we're
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going to use NVIDIA's proprietary gam stream technology
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with a shield handheld Android gaming system to see how close it comes to
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valve's more open solution NVIDIA's
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Advantage is that due to its closed ecosystem they can keep tight control
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over the data chain and fully leverage their own Technologies such as the
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built-in Hardware h264 video encoders and decoders on their Graphics
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processors however NVIDIA's disadvantage here is that they're running wirelessly
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that's how they advertise game stream uh NVIDIA also has the benefit of tightly
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controlling the settings at which games can run and they allow only a maximum of
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720p 60 FPS compared to the 1080p 60fps
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that we were able to run with a wired connection on a steam inhome streaming
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setup so gam stream ads about well about
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the same 74 milliseconds compared to our CRT which seems pretty good considering
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that it's wireless because it's wireless though it is subject to interference and
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you won't get that 74 Mill second delay
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consistently since you won't always be right next to the router the way that we
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are for our controlled testing scenario 3 addresses an imbalance in the previous
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two examples by taking our steam machine and turning it down to 720p 60fps than
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running it wirelessly so it's more equivalent to the shield the ASUS 87i
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Deluxe motherboard that's running in here has onboard dualband AC Wi-Fi which
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should be basically equivalent to the Dual Band n Wii on the shield because
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we're connecting to an N access point going Wireless with steam in home
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streaming adds about there's that number again 74 milliseconds compared to our
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CRT so performance was pretty much the
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same as the shield in terms of lagginess and very playable but not something that
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I would actually recommend doing Shield runs on a small built-in display we only
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used the HDMI output to go to our bigger one to control the variable of the
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displays input legs so that we got comparable results so compressed 720p
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images will normally still look really good and really sharp on that tiny
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little display but for something bigger like you'd be running on a steam machine
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like a TV or a monitor I would really recommend a wired connection so you can
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game at 1080p scenario 4 is an
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open-source streaming app called Limelight that keeps getting brought up
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to me whenever I talk about inhome streaming
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Solutions it works yes but I hope this
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video serves as a demonstration of why I don't talk about it much yet and why I
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don't care about it much yet it works on pretty much any reasonably powerful
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Android device which is really cool but it's just not even in the same ballpark
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as the others and in my experience does not provide a playable experience on
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either of the supported devices I own an NVIDIA shield and an HTC1 our measured
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latency was about 98 milliseconds but
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unfortunately the image quality was lower than any of the other
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Solutions with more frequent unplayable stutters in my testing so in summary the
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best streaming Solutions we have are tripling the delay that you experienced
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when you upgraded from a CRT to a good quality LCD but in that time they're
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encoding an image sending it over a network then decoding it 74 milliseconds
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of display lag is noticeable but it's definitely playable for most genres of
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games I actually beat the first couple worlds of Super Meat Boy streaming on my
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shield I'll be it not as easily as I can when hooked up directly with a wired
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controller but I was able to do it 100
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milliseconds becomes too much to deliver a satisfactory game experience for
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anything but slow paced perhaps turn-based gaming for me and while your
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sensitivity may vary the takeaway today is that gaming on the machine you're
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directly attached to is still better we're talking 22 milliseconds compared
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to about 75 so we're talking about a 3X
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betterness Improvement even with an LCD monitor compared to a CRT versus
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streaming it's still the best but
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quality local game streaming Solutions are adding about another 50 milliseconds
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of leg which means that we can achieve very playable results today if we
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control the additional latency introduced by other parts of the chain
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such as wireless gaming controllers or leggy TVs and in a generation or two if
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encoder and decoder Hardware can be improved we could be able to get pretty
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close to the performance of sitting in front of the device which is extremely
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exciting the future is going to be awesome folks I hope you enjoyed this
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video like it if you liked it dislike it if you disliked it leave a comment and
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let me know what's your sensitivity like did you really notice when you went from
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CRT to LCD do you notice the difference from one LCD to another cuz I certainly
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do and have you tried in home streaming or inidia shield with its gam stream
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technology and did you find it very playable would love to hear from you
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guys and uh I'm sure I have a standard
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intro but I've completely forgotten it now don't forget to subscribe peace
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n