[maemo-users] UI-Performance experience with N800

From: Eero Tamminen eero.tamminen at nokia.com
Date: Thu Sep 6 10:27:36 EEST 2007

ext Clemens Eisserer wrote:
> I just got my N880 and I really think its a cool device. It now looks
> in my opinion even more professional than the old one and has matured
> to a "real" product.
> However from the software-user point-of-view I am not so happy with
> it, especially when it comes to performance.
> Every menu you open/clode every; every windows which appears or is
> hidden, every Drag&Drop action or scrolling, or SplitPane-Resizing
> (e.g. in the filechooser), or selecting a list. Everything that has to
> do with intercating with the UI is really damn slow :-/
> Its almost the same than with the 770, however I thought that maybe
> the 2 years additional time to work on the platform and the faster
> hardware could have improved the situation - but it even feels slower
> than IT2006 on my 770. I don't know but maybe GTK simply was the wrong
> choice? (I have to admit that I am a known GTK hater so please take
> this question with the needed grain of salt).
> As soon as you moove something you see/feel the stuttering, and
> destroyed areas are repainted really slow (more complex windows like
> the info-dialogs of the audio player take 300-600ms to repaint!)

There's a tool to get fairly exact measurements for these:
* Install "xresponse" from the Maemo repositories
* Open menu etc. from which you can invoke the dialog
   and do something like this in SSH console:
     xresponse -w 4 -c 400x200
   I.e. simulate a stylus tap at co-ordinates 400x200 (change
   this to correct one) and list screen updates during the next
   4 seconds (could be smaller)
* If you want to monitor screen updates all the time, use:
   xresponse -w 0 -i

Our generic UI requirements for responsiveness are:
- All user actions need to give user response within 0.5 seconds
   (e.g. when tapping any menu item, the menu closes in less than
   0.5 secs to indicate that something happened)
- If an operation (such as opening a dialog) takes more than
   3 secs, there needs to be banner about the operation

These are intended for device that is otherwise idle.

The requirements are not very tight, but that's because they are
generic ones, everything on the device has to fulfill them.  If you
can measure with xresponse that something doesn't fill the above
requirement, please file a bug report.

Most used functionalities should of course be more responsive (0.1 secs
would be very good).  If something like that is annoyingly slow, please
file also a bug report with information how to measure it and what
timings you got on average (you need to measure things a few times to
get reliable measurement).

	- Eero

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