The program defaults to using up to 512 MB of memory. This is sufficient for most common applications of the program. However, simulations with Basin Models that include many elements, use long time windows for continuous simulation, or make use of gridded meteorology can require significantly more memory. Computing large simulations with insufficient memory may cause the program to abruptly cease operation.

The following files need to be changed to allow the program to use more memory than the default 512 Mb:


<HEC-HMS Install>\HEC-HMS.cmd

<HEC-HMS Install>\HEC-HMS.config


<HEC-HMS Install>/hms

In all three files, search for the string -Xmx512M and replace the 512 with the number of MB's you would like to allow the program to use.

The amount of memory you can use depends on your operating system. A typical computer using Microsoft Windows® or Linux® can usually use up to 1,350 Mb. These are general guidelines and your situation will depend on the specifics of your hardware and other processes that may be executing at the same time as the program. In no case should you attempt to use more than half of the physical memory in the machine since other applications and system processes also require memory resources.