I have a couple of servers configured with 2.6GB RAM. My NT Admin came in the other day and told me he had been looking at performance on an unrelated server and discovered that he needed the /PAE switch enabled in order to see the full 16GB available on that server.
He then convinced me that we needed to set the /PAE switch on all our SQL servers with more than 2GB of memory.
I checked sp_configure after setting /PAE and both servers show that 'max server memory (MB)' is 2559 (which is what I would have expected).
Do I need to do something more? Is the /PAE switch required in my case?
Personally, I would not set that switch for servers running less than say 5GB of memory. There are two switches that can be added to boot parameters (ok, I don't know exactly where...)
/3GB allows applications to use up to 3GB of memory (standard limit is 2GB on a 32 bit system)
/PAE allows applications to use a heck of a lot more memory.
In both cases, you have to remember that the operating system (and any other applications) want to use some of that precious memory, too. If SQL Server is eating all 2559MB of memory, you could end up with the paging file getting hit an awful lot more than you would like. In your case, I would definately avoid both switches, and let the OS use the other 500MB of memory.