W3/W510 HDMI/WiFi issue.

The more I look, the stranger I find.

 

In testing my tablets Wifi behaviour using speedtest.net. Both W3 and W510 report download speeds an order of magnitude slower when the HDMI is connected. 20ishMB/s when not connected and 2ishMB/s when is (several different tests). QOS setting has no effect.

 

Note: have seen as high as 6 MB/s with HDMI connected but erratic, always much slower than not.

 

Now this raises some possibilities:

1) when HDMI graphics are in use, the graphics drivers walk all over the WiFi.

2) when HDMI is connected, WiFi is automagically optomised for screaming video rather than TCP/IP.

3) ????

 

I do not have any screaming video services. Has anyone noticed a performance impact when watching a online movie with W3 or W510 connected to a big screen ?

 

ps tests with external WiFi adapter indicate that (1) is likely;

24" Monitor 1920X1080: 26 MB/s

24" Monitor 1280x800 :  37 MB/s

W3 display only:             39 MB/s

disconnect external adapter

W3 display only:              14 MB/s

 

So two factors:

1) W3 WiFi is not as strong as W510

2) Extended displays particularly 1920/1080 severely impacts WiFi speed.         

Answers

  • elemein
    elemein Member Posts: 20 New User

    Is streaming video not already TCP? I had no idea it was UDP.

  • padgett
    padgett ACE Posts: 4,532 Pathfinder

    Can be either UDP or TCP though UDP is more common for things like RTSP. Netflix uses something called DASH (Dynamic Streaming over HTTP) in which each chunk is checked for bandwidth and the quality varied by speed, This enable HD quality if the downward bandwidth exceeds 10 MB/s and drops to SD at 2 MB/s. Video on Demand (cable boxes) generally use H-263 or H-264 and Multicast for live TV.

     

    So to whether TCP or UDP the answer is "yes" (plus IGMP).

     

    More I look at it the more it looks like the WiFi SDIO card is competing with the Intel video drivers for priority and the higher the video demand, the less CPU time the WiFi gets.

     

    ps also tried with Windows to Go whick uses the Acer driver stack but has none of the included W3 APPs. Total space used on a 32GB DT is 11.4GB. WiFi speed is slightly (about 20%) higher but is still badly affected by a 1920x1080 display.

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