Working with large microarray datasets in J-Express can be very memory demanding. If you are working on a computer having 1GB RAM or more you can change the maximum memory that J-Express/Java is allowed to use. Go to Settings menu in J-express and choose Options, the Settings window will open, choose the Files/folders and java settings tab. The default memory setting in J-Express is set to 256MB RAM for both minimum and maximum memort usage. These values can be changes in order to make J-Express work faster.
32-bit OS: Java can't handle more than maximum 1600GB RAM.
64-bit OS: There is no memory limit for Java on 64-bit OS.
IMPORTANT: Do not set the maximum memory usage to the maximium amount of memory in your computer. The computer need memory for other processes that is running at the same time as J-Express. Have at least 512MB-1GB memory free for these processes.
Change the memory settings by simply add an appopriate MB-number for you computer and press Enter. You can change both the minimum and the maximum memory usage, but the maximum is the important one if you want J-Express to work faster.
In the same tab ( Files/folders and java settings tab in the Settings window) you can also set the J-express folder paths. Normally these paths should be filled out correctly when installing J-Express. The paths for your J-Express will probably be different from the paths in the example above.