Maximum image size
The maximum supported image size is about 15 000 x 10 000 pixels (tested on Windows 7 and 8, 64 bits, with 4 GB RAM, a common configuration for these days), but there are a number of factors that can affect the maximum image size that the program can handle.
System RAM size.
Free disk space available for virtual memory swapping.
Operating system policies on memory allocation.
The display driver can also play an important role.
Number of undo steps or undo limit that the program stores. Set undo limit to a lower value to save memory.
Number of simultaneously opened images.
Number of running programs.