02-14-2023, 02:09 AM
Intel became unable to increase CPU frequencies so multiplied the CPUs and now the performance is handled by application code.
Not everything is easy to multi-thread. I see than when I scale, all my processors max out, but generating plasma is on one CPU only.
Fundamentally to be able to edit very big image in a small RAM, Gimp cuts the image in tiles and works with tiles on disk. In practice to increase performance, some of that disk space is cached in RAM (this is the "tile cache") and on many modern system it is big enough to avoid putting things on disk most of the time. So this tiles file and cache is really Gimp's own swap. You could of course define a tile cache much bigger than you available RAM, and Gimp will use that and the system would do the swapping. Using Gimp's own swap is normally a better solution because 1) you can hope/expect that Gimp accesses it in some manner optimized for its own processing, and 2) only Gimp is affected by the swap, other apps in the system can continue to use all the RAM they want/need.
A good size for the tile cache is the amount of free RAM you have before you start Gimp (ie, what is left after booting and starting you favorite apps). On a system like yours I would try 6GB, and be ready to downsize that a bit (5G, 4GB) if the OS swaps.
Not everything is easy to multi-thread. I see than when I scale, all my processors max out, but generating plasma is on one CPU only.
Fundamentally to be able to edit very big image in a small RAM, Gimp cuts the image in tiles and works with tiles on disk. In practice to increase performance, some of that disk space is cached in RAM (this is the "tile cache") and on many modern system it is big enough to avoid putting things on disk most of the time. So this tiles file and cache is really Gimp's own swap. You could of course define a tile cache much bigger than you available RAM, and Gimp will use that and the system would do the swapping. Using Gimp's own swap is normally a better solution because 1) you can hope/expect that Gimp accesses it in some manner optimized for its own processing, and 2) only Gimp is affected by the swap, other apps in the system can continue to use all the RAM they want/need.
A good size for the tile cache is the amount of free RAM you have before you start Gimp (ie, what is left after booting and starting you favorite apps). On a system like yours I would try 6GB, and be ready to downsize that a bit (5G, 4GB) if the OS swaps.