If your chips aren't very large, you can fit multiple copies in the reticle. E.g., if the litho machine has a 40mm by 50mm reticle, and you're making a 10mm by 10mm die, you can expose 20 dice at a time. It's usually worth it to go out to the edges even if you only get a few complete chips from the exposure. I can't find a wafer picture for Nvidia's GV100, but presumably a giant chip like that uses the whole reticle, so I don't expect to see partial chips on its wafer.