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Java on Windows : Virtual memory vs. Physical memory

5:29 am on Jul 21, 2005 (gmt 0)

10+ Year Member

I want to run 5 instances of my java app on a Windows machine. (Please don't flame me about Windows. I love *nix too but its necessary for this project.)

I need to allocate plenty of memory for each instance so I run them like so:
java -Xms512m -Xmx512m

Five instances at 1/2 GB each is around 2.5 GB of memory required. So I put 3.5 GB of physical RAM into the server. I run the five apps and I observe the following in Windows Task Manager - Performance:

Physical Memory
Total : 3.5 GB (roughly)
Available : 2.5 GB (roughly)

PF Usage : 3.14 GB

Am I reading this wrong or is this telling me that only about 1 GB of physical RAM is being utilized and 3.14 GB of virtual memory/paging is being used? If thats the case then how do I run Java to ensure that I'm not losing performance due to paging?

12:20 am on Aug 5, 2005 (gmt 0)

10+ Year Member


You can try changing the amount of virtual memory the system uses if you like:

*This is for Windows Server 2003

Right click on 'My Computer'
Select 'Properties'
Select 'Advanced' Tab
Click 'Settings' button under 'Performance category
Select 'Advanced' Tab
Click 'Change' button under 'Virtual Memory' category

Click on the desired drive up at top and set the corresponding values below to your specifications.