My desktop is similar age, bios says 2005, CPUX utilty says mainboard 2013 but a bit like Washingtons axe, many bits replaced over the years, 8 GB memory + a 2.9 GHz Athlon II ( 
)
A 5000 x 5000 image + mask + a single layer under, gets up to 600 MB in memory, not inconsiderable.
Taking into account the mask, a 10 deg. rotation takes 52 seconds , with the mask applied 37 seconds.
That is the overhead rotating the mask as well, a good percentage.
)A 5000 x 5000 image + mask + a single layer under, gets up to 600 MB in memory, not inconsiderable.
Taking into account the mask, a 10 deg. rotation takes 52 seconds , with the mask applied 37 seconds.
That is the overhead rotating the mask as well, a good percentage.