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Changes between Version 2 and Version 3 of Latency

04/07/20 08:39:14 (11 months ago)
Antoine Martin



  • Latency

    v2 v3  
     4{{{#!div class="box"
     5== Minimizing latency ==
     7Everyone wants low latency screen updates, but not everyone gets it.
     8The server should be able to self-tune adequately in most cases.
     10To be able to minimize latency, it is important to understand where the latency comes from in order to be able to target what can actually be lowered in the chain. (see ''understanding latency'' below).
     11Some delays cannot be reduced: your connection latency is dictated by the laws of physics and there's no way to change them, it is usually impossible to affect the delays introduced by the operating system or the hardware.
     15Here are some common misconceptions:
     16* setting `TCP_NODELAY` on the socket will reduce latency: that's not necessarily the case, and it can be counterproductive in some situations (ie: limited bandwidth, tunnelled traffic, etc - see #619)
     17* disabling picture compression (ie: RGB only): if the CPU can compress faster than your network can send, then may actually take longer to process the screen updates
     18* plain TCP mode is faster than SSH: it usually is, but not always
     22So, how do you make things go faster?
     23* use a hardware encoder: [/wiki/Encodings/nvenc NVENC]
     24* application content-type: making sure that xpra guesses correctly (#1952)
     25* give some hints about what sacrifices to make:
     26 * quality: sacrifice latency, framerate and bandwidth consumption in favour of perfect screen updates
     27 * speed: sacrifice bandwidth consumption in favour of better latency (usually) and framerate
     29If that is not sufficient, you may want to report the problem so we can advise you on how best to tune your system, and fix xpra if that's what is required.
    532{{{#!div class="box"
    6 Understanding latency.
     33== Understanding latency ==
    835From the moment the user does something using the keyboard or mouse until he can see the result of this action on screen.