I have multiple large rasters. Their 5 percentile and 95 percentile are needed to be calculated. After loading the rasters to the ArcMap, I am using the following codes - import numpy import arcpy rasters = ["raster1.tif", "raster2.tif", "raster3.tif", "raster4.tif"] for i in rasters: array = arcpy.RasterToNumPyArray(i,nodata_to_value=10000000000) marray = numpy.ma.masked_values(array,10000000000) del array percentile5 = numpy.percentile(marray.compressed(),(5)) percentile95 = numpy.percentile(marray.compressed(),(95)) del marray print percentile5 , percentile95 For the first two rasters, it provides the percentile values. For the third raster, it is showing memory errors. I am using ArcMap 10.5 in desktop with 32 GB Ram. Is there any way to get rid of this memory issue?