Re: [Gimp-user] Image doesn't move smoothly

[Steve Kinney <admin pilobilus net>]

On 04/13/2018 11:42 AM, Brombur wrote:
> I decided to give gimp another go. I've updated my video and run an ok pc with
> decent stats but when I use gimp and try to move any image, of any size or
> resolution the image lags when i position it. even on simple single color
> layers. If i make a red box and try to move it the image is so choppy it looks
> like Im watching a picture download circa 1995.
>
> Any idea? I don't have this problem when I run Pixlr and when I ran my demo of
> photoshop.

The only times I have seen the GIMP act like that (15+ years across
/numerous/ machines and operating systmes) it was always a memory issue,
typically due to working on a fairly huge image with many full size
layers and LOTS of "undo" steps saved.

Fist check the size of the images you are working with, in pixels:  This
is shown in the canvas window title bar, after the name of the open
file.  If the X and Y dimensions are in the multiple thousands of
pixels, that could be the problem.

I will guess that you are using GIMP 2.8, not a development build; if
not, this may be incorrect (or not):  Go to Edit > Preferences, and in
the Environment menu (should be the one that opens by itself) and check
the Tile Cache Size item.  "When the amount of pixel data exceeds this
limit, GIMP will start to swap tiles to disk."  That sounds very much
like what you are seeing when you move things around on the canvas.  I
normally like to set this limit to about half of total system RAM, more
if the machine has a huge amount of memory, less if the system doesn't
have memory to spare.

On my laptop which does not have a huge amount of memory, I start seeing
a /small/ amount of lag when moving image-sized layers at about 2500 x
2500 pixels - noticeable, but does not slow my workflow down.  At 4000 x
4000 pixels it gets more noticeable; I would have to adjust my maximum
image size setting (same menu as above) to test at 4500 px or above...

Hopefully this will put you on the trail to a solution.  If none of the
above seems to apply, check all running processes on the machine to see
if some background process is eating up a huge amount of system memory.
poss8ible.

:o)