I am running Windows Server 2003 STD Edition. Am I correct in assuming that the maximum installed memory is 4GB? I run my backups and Exchange Server 2003 on this machine. I have the /3GB and /userva=3030 switches in the boot.ini file. Are these beneficial for Exchange? Also can someone please educate me a little on PAE and AWE? Thanks

The Exchange Server computer cannot efficiently use more than 4 GB of RAM. Exchange Server does not support instancing, Physical Address Extension (PAE), or Address Windowing Extensions (AWE). Therefore, 4 GB of RAM is the maximum amount of memory that an Exchange Server computer can efficiently use. Besides add /3Gb and Userva=3030 switch in boot.ini,you also should modify HeapDeCommitFreeBlockThresholdregistry key value to 0x00040000 , please reference this article How to optimize memory usage in Exchange Server 2003.

Thanks very much for the reply. I have a follow up question. Since I've added the two switches and edited the registry I've noticed a drastic decrease in memory usage in Task Manager for store.exe. It might be my imagination, but it also seems like Exchange performance has decreased as well . . . large messages seem to take longer to open. The inetinfo.exe process also seems to be using more memory. Are these results intended? Is it because of IIS (OWA) or the fact that my backup program (Symantec Backup Exec), which uses MSDE of SQL 2005 is using more memory because of the added switches? Thanks, George

Asmy experience it's will not decrease exchange performance... If you still feel performance is down, suggest you flow this article to get more help performance issue information Description of the Exchange Server Performance Troubleshooting Analyzer tool