Description
You may get this warning in the Quartus® Prime software version 15.1.You see this warning if your computer has less than the recommended amount of physical RAM for the Altera device you are using e.g. for Arria® 10 18-48 GB RAM are required.
Resolution
To avoid this warning, install the recommended physical RAM in your computer as mentioned in the Quartus Prime Standard Edition Software and Device Support Release Notes Version 15.1 (PDF).
Altera recommends that your system be configured to provide virtual memory equal to the recommended physical RAM that is required to process your design.