Ruby 64-bit, released first quarter 2016, is up to 45% faster on big jobs, and uses RAM beyond the 2-gigabyte limit.
Machines with more than 4-gig RAM are becoming more common. If you are using the 32-bit version of Ruby, regardless of how much RAM you have installed, Ruby can access only 2-gig. This is a Windows limit.
On a 4 gig machine running Windows 7 the default memory threshold for imports is 70%.
If you have an 8-gig machine running the 32-bit version of Ruby, then the maximum threshold should be 50%, and if a 16-gig machine, then 25%. If you don’t reduce the memory threshold, then Ruby may try to use more than its allocated 2-gig, and you will get the dreaded EEFFACE error (see next post).
There is no 2-gig memory limit for the 64-bit version of Ruby. However, you still need to leave enough free RAM for the operating system, so the setting should be <90% for a 16-gig computer and <80% for an 8-gig computer.