blender render in splitted image for images that dont fit in ram

blender_render_split_image.py

import bpy
import os

# Usage:
# blender -b FILE.blend -P blender_render_split_image.py

# Backup from
# https://stackoverflow.com/a/38223109

cut_into = 10
output_folder = '//renders'
rndr = bpy.context.scene.render
rndr.use_border = True
rndr.use_crop_to_border = False

for row in range(cut_into):
    for col in range(cut_into):
        filename = "chunk_{}_{}".format(row + 1, col + 1)
        rndr.filepath = os.path.join(output_folder, filename)
        rndr.border_min_x = (1 / cut_into) * row
        rndr.border_max_x = (1 / cut_into) * (row + 1)
        rndr.border_min_y = (1 / cut_into) * col
        rndr.border_max_y = (1 / cut_into) * (col + 1)
        
        bpy.ops.render.render(write_still=True)