Blender crashes with very large picture size

I need to render very large images to be printed in high quality as a photo on A2 paper.
However my machine crashes on it, small images are OK, but large ones not, despite that i use CPU rendering and have 24Gig ram. (the final jpg is not 12 Gig or so…).

Anyway i’m asking it here as i wonder is there a way that i can tell blender, to save the image after every tile got calcultate, or like update an image ??. (i’m running blender on an octocore).

elaborate !
Bl cycles ?

render size in pixels ?

happy bl