I am a long time DM that has just recently been forced to move to digital ttrpg gaming [due to moving recently] and have come across a neat little program called AutoRealm. It looked like the perfect way to make maps for my games so I downloaded and installed and as I use it I notice a lot of issues with it. Things like long load times [upwards of 15 minutes at program start and upwards of 3 when switching map icon sets], zoom and pan issues [slow and 'jagged' and tends to leave the maps with 'warps' at the places that where moved 'off screen'] among other minor issues.

The program is an older one so I'm not holding my breath for any updates or anything but maybe someone that has gotten it to run smoothly can give me some tips. I posted some info about my system in case its relevant [again new to all this]. I am willing to look into other programs for mapping but if you are going to suggest a new program please keep the following in mind:
1.) The program MUST be free, if I could afford CC3 or the like I would not be trying to get AutoRealm working
2.) I would greatly prefer the program be for making maps, it does not have to be for making fantasy or game maps specifically though.
3.) I already have a program for making dungeon maps so I'm looking for something to make World/City maps
4.) I use Roll20.net to host my games so the program must be able to export finished maps in one of the more common image formats [jpg, jpeg, png ect]

Any and all help/advice would be greatly appreciated, and of course happy gaming!

-System-
Win 8.1 Pro [x64]
Intel Core 2 Duo E6580 @3.00GHz
DDR2 Ram [6Gb]