Re: [Gimp-developer] gimp 2.8 prohibitively slow

[Aaron Paden <aaronbpaden gmail com>]

Hello, Liam. I've tried your suggestions and have gotten some pretty 
good results. My large image used for this test is still not practically 
editable, but I was having problems even with relatively small images in 
gimp, and these workarounds have really improved gimps responsiveness 
and usefulness for me. The brush can now (mostly) keep up with my hand! 
:) Thanks for your insight.

One thing I noticed is that actually loading the images is very 
expensive, and gimp doesn't behave very well while it's happening. It 
took several minutes to load the large image, and while it was doing it, 
X was mostly unresponsive. Is there room for improvement here?

On 07/18/2012 11:01 AM, Liam R E Quin wrote:
> Try increasing the tile size in your gimp preferences e.g. to two
> gigabytes (and make sure you have at least three gigabytes of swap
> space).
>
> To work with this image in gimp on a 32-bit system you will need:
>
> (1) to have as large a tile cache size as you can -that's the amount of
> memory gimp devotes to keepng the image in memory instead of on disk
>
> (2) have the Undo History window in your dock, and use the button at the
> bottom right to Discard Undo History roughly every 30 to 50 brush
> strokes. Unfortunately I don't think you can bind that to a keyboard
> shortcut, so you need the undo history window docked.
>
> (3) save work frequently as xcf.gz - do not overwrite the same file each
> time, in case you run out of memory while gimp is saving the file. Save
> and Expert go much faster if you discard the undo history first.
>
> (4) turn off thumbnails everywhere you can,
> e.g.,
> in edit/preferences/interface,
>    turn off Enable Layer & Channel Perviews
> in edit/preferences/Toolbox,
> . turn off the "show active image"
> in edit/preferences/Image Windows, you may want to
> . turn off Show brush outline
> this may make painting faster but unuseable, though.
> . set pointer mode to rendering to crosshair only
> . set pointer rendering to black and white
>
> (5) make sure your gimp title bar shows the amount of memory in use - if
> it doesn't, go to Edit/Preferences under Image Windows, Title and
> Status; for Image Title format I have
>
> %D*%f-%p.%i (%t, %L) %wx%h %m
> (the default except for adding %m for memory)
> and for Image status bar I have
> %n (%m)
> (the default)
> That way if the status bar is saying something else, e.g. while you're
> painting, you can still track memory usage easily.
>
> (6) in edit/preferences/colour management,
> . set Mode of operation to No color management
>    (I just notice "colour" is misspelt there)
>
> (7) do not use a theme with transparency. In Windows, use the classic
> windows theme. In Linux, do not use compiz or a compositing window
> manger (the ones that put drop shadows under windows), because these to
> tend to reduce (sometimes halve) painting speed and increase memory
> usage.
>
> Hope this helps.
>
> Liam