I would double your memory to start with but there is an issue with an out of memory error even if you have 4gb. I purchased Tongass Fjords, have 4gb and was receiving this error even though my total memory usage was a little over 2gb. I don't have the link but if you do a Google search you will find a tweak that will fix this. It is a command line that you run. I did it and have not had the error since.