Re: Gtk_Tree_View, drawing speed

[Vlad Volodin <vest 84 gmail com>]

Hello Arne,

Is it really necessary to refresh updates 400 times per second? To be
honest, me as a human will not notice all these changes. What do you
think about doing updates once or two times per second? (like all task
managers do) E.g. you can collect all values that come from the
hardware and display the average value only.

Kind regards,
Vlad

2012/9/26 Arne Pagel <arne pagelnet de>:
> Thank you for this hint,
>
> I tried it and indeed I notice a speedup, but just factor ~1,3.
> There must be something more.
>
> I removed all columns expect the "Value" column, and now I notice a speedup
> factor of ~3, if I remove just one column, is see a speedup factor of ~2.
> Now I am sure that there is some processing on cells where the corresponding
> data in the treestore are not touched.
> If I remove columns on the first treeview which is using the same tree-store
> I see no effect.
>
> What is interesting that I now notice also a speedup of my single elements
> objects, there now I can achieve an update rate of 570 requests per second.
>
> - -
>
> I just noticed that I can't compare the single element objects and
> structured objects in that way I did before,
> but anyway, with the column removing I see some potential for speeding up
> everything.
>
> Of course the given value of 570 requests per second is not the design goal
> of the program.
> But later I want to have many structured objects in the treeview with an
> acceptable update rate and not 100% CPU load.
>
> regards
>   Arne
>
> Am 26.09.2012 10:51, schrieb jcupitt gmail com:
>
> > On 26 September 2012 07:09, Arne Pagel<arne pagelnet de>  wrote:
> > > Do you see any other option?
> >
> >
> > Have you tried setting the fixed-height hint on the treeview?
> >
> > By default treeview supports variable-height rows. This is great, of
> > course, but there is a performance penalty: whenever the model
> > changes, the view has to rescan the model and recalculate all the
> > heights. If all your rows are the same height, and they might be from
> > looking at your screenshot, you can set the fixed-height hint and get
> > treeview to just sample a single row.
> >
> >
> > http://developer.gnome.org/gtk3/stable/GtkTreeView.html#gtk-tree-view-set-fixed-height-mode
> >
> > John
>
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