"A bit more" is an understatement. For me 8k takes about 5 minutes and 16k takes about 3 hours.16 will take a bit more but nothing like the RWG in game.
Oops, I should have been more clear. While I did need to up RAM allocation to 10G, I generated several 16k maps with no problem. The reason I reverted to an 8k map was RAM usage when playing a 16k map. It starts out at +10G and if I exit to the main menu and continue the game crashes with OOM.16k is really cutting it close for computers without lots of ram.I suggest turning off the preview map rendering for really large maps to save some memory. (or use the classic preview)