Windows 4GB limit

[humbletech99]

I've been going round and round on the web trying to find out about the 4GB limit on Windows, but I'm not 100% having seen some arguments about what it means and if/how to get around it.

I have an XP Pro workstation with 4GB ram in it, of which it can see around 3.5GB. I'd like to squeeze out the remaining half a gig since I'm running Virtual PCs on this box.

I also have some 2003 Servers that may need more than 4GB of ram (Opterons running 32-bit 2003 Server).

1. Does the /PAE boot switch only work on Intel processors or AMD as well?

2. Does the /PAE boot switch work on XP Pro or just on Windows Servers?

3. Does the /PAE switch allow you to use more than 4GB physical ram on a 32-bit OS?

4. Can regular apps use more than the 4GB of ram if /PAE is used? (eg. Virtual PC, Vfox etc)

[Eight-Oh-Eighty-Eight]

I'm not sure about your specific questions, but there should be no good way to allow you to use more than 4 gigs on a 32 bit system. It would require some weird software manipulation and would probably hurt performance. The largest number that can be stored in a 32 bit system is 2^32 which equals 4,294,967,296 which works out to 4 gigs. Your best solution is to begin the migration to a 64 bit system, which I know can be costly, but it sounds like that's what you need if you need more RAM. I believe that a 64 bit system can address 16 TB of RAM (if memory serves) so that should be enough until we hit 128 bit systems.

-8088