Balancing Memory Usage

If Microsoft Exchange Server uses all of the memory you can give it, up to the total size of your information store, your entire database is in memory. The minimum amount of random access memory (RAM) recommended for Microsoft Exchange Server is 24 MB, but testing has shown that 64 to 128 MB of RAM provides much better performance than an upgraded CPU.

If memory is a performance bottleneck, you can do one or more of the following:

• Add more RAM.
• Increase the size of your pagefile. In Control Panel, choose System, and then select the Performance tab. Under Virtual Memory, set a large pagefile for Paging File Size For Selected Drive. You can approximate the pagefile size by adding 125 MB to the amount of physical RAM available on your server. For example, if your server has 64 MB of RAM, you should set your pagefile size to 189 MB.
• Move the pagefile to a separate physical disk.
• Ensure that Windows NT Server is optimized for network applications. In Control Panel, choose Network, select the Services tab, and then select the Services tab. Select Server in the list of installed network services. Choose Properties, and then select Maximize Throughput for Network Applications.
• Restrict the amount or type of mail users can send.
• Move Microsoft Exchange Server components or other applications to another server.
• If your server is paging excessively, adjust the size of the database buffer caches by typing perfwiz -v at the command prompt. You should reduce the size of the buffer cache by 10 to 30 percent. Use caution when changing this setting. Make small adjustments, and monitor the results until you are satisfied with the changes.
• Move some or all mailboxes and public folder replicas to another server.