Using /3GB or PAE with 32bit applications
Posted on 2010-09-03
We have an application running on a Windows 2003 Server Enterprise 32bit. The application itself is 32bit too. The server is running on VM and has 4GB RAM allocated to it.
The application seems to be eating more and more memory! Whilst we are looking into what is causing this (memory leak, patch etc), our server guys have advised thay they can allocate more RAM to the server. BUT - they will need to use the PAE switch or 3GB switch in order for the OS and application to 'see' this extra memory.
Not being a server admin, I was hoping a memory expert could help me out here.
Firstly, does the /3GB switch actually allow for the OS/app to see more memory? I thought it only changed the allocation of virtual address memory from 2GB:2GB to 3GB:1GB app: kernal ratio?
Secondly, I guess we can use PAE, but will this help if the app is not 'PAE' aware?
Thirdly, are there any disadvantages to using PAE, or is this recommended to 'trick' the OS into seeing more than 4GB RAM?
Finally, given that the server is a VM, are there are any disadvantages from a VM perspective (assuming we have enough RAM on the host).
Many thanks in advance!