Hi Stephen, the keep-going option effects only the creation of individual tiles. Your problem happens when the overview map is calculated, the problem is not related to 3GB or 4GB, it is about the limit in this single img file. As I said you are probably putting too much information into your overview map, to solve the problem you have to change your style or the overview-levels statement. If you don't create files fort the PC you don't need the overview map, so maybe use the option --no-tdbfile. But this will also tell mkgmap to avoid the creation of the ovm*.img files. Gerd ________________________________ Von: mkgmap-dev <mkgmap-dev-bounces@lists.mkgmap.org.uk> im Auftrag von Steve Sgalowski <steve.sgalowski@gmail.com> Gesendet: Mittwoch, 30. März 2016 02:07 An: Development list for mkgmap Betreff: [mkgmap-dev] img limit what is the max limit on the gmapsupp .img file size? is there a reason why it wont go past 3 gb , even with keep going switch applied Stephen