memory usage

Jan 4, 2013 at 8:47 AM

Hello everyone

can anybody explain me why if I load a raster map with demomap (bgd format, 100 Mb roughly), memory usage increases more than 3 times the bgd dimension (say to 350 Mb)?

And why after I remove the layer only 100 Mb is freed? (seems the original dimension of my input raster file)

Thank you