Thanks to all who responded with useful comments.
It isn't entirely clear from the comments when gimp starts up, but the
tiling cache should indeed be almost as large as physical memory,
allowing some for other uses (such as the OS).
Increasing to 1500Mb on a 2G system was a huge improvement. I have not
sought to tune that number, not doing enough of these to make that
worthwhile. The undo suggestion of Alastair Robinson is also probably
very good for continued manipulation.
As I think the original posting indicated, allowing virtual memory to do
the work, is for whatever reason not the answer.
I suggest modifying the documentation to read something like:
Increasing tile memory cache will continue to yield benefits until you
totally saturate physical memory. If you can afford to give nearly all
your physical memory to gimp while you are running it, and you need to
process large images, then do so.
> If the OS has better virtual memory than what available to gimp, >then
you would want to use that one. In Linux, I think in most >cases, you
would want to use the (often in multiple disks) swap >partitions/files
available to the OS.
Evidently not, as in my first post.
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