Memory management

[rickk]

Using Gimp 2.10.30 (32 bit) I was working on a 15,000 x 20,000  size image, and noticed that gimp was reporting the project size as 11.8 Gig (see attached).  Once I eventually exported the image... the final file size was only 135 MB.  But, I'm surprised that 32 bit gimp can count up that high?   What was actually going on behind the scenes allowing this to happen?




Additionally, this particular project involved my "quilting" together 10 fairly large tiles of a map, into a single image. This required SUBSTANTIAL moving, tilting, scaling, and redoing a large number of operations in order to get all the roadways to line up properly.

SO there is little doubt in my mind that I had a considerable amount of memory tied up, in the form  of "undo" operations.

Is there a good way to tell gimp to release "undo memory" during the course of a protracted multi stage project.

For example, once I had 6 of my 10 tiles edited and placed perfectly,  all the memory being held to save the "undo" operations up to that point, could be put to better use if released.

If that seems like an unusual ambition, consider that I came to this point the hard way.  The first time through the assembly of this quilt,  4 hours in and working on the 10th tile.....I did run out of memory....and the end result was not rewarding.  

So, this question is more or less a think-back to what I coulda/shoulda/woulda have done.

[Ofnuts]

A 200Mpx, any layer is 1.2GB, so the undo stack grows fast since it just makes copies of layers. You can tweak Edit ➤ Preferences ➤ System resources to reduce the minimum amount of undo levels. You can also reduce the tile cache size to make sure Gimp fits in your RAM (but it can become very slow instead.)

[rickk]

Thanks for that. I'm guessing that a restart would be necessary for the change in settings to take effect. So at that point I would have already had to save my work, and re-start before continuing, which serves to clear the undo memory anyway.

I was just hoping for an easter egg, I guess, thinking there might be a way to delete undo steps similar to deleting layers in the layer dialog....my bad. ahh well.......