won't see > 4.5GB memory

[jlkj2]

i have a Win2K Advanced Server SP4 install on a Dell PowerEdge 2650. I was
running with 3 GB (using /PAE switch in boot.ini). I've tried upgrading it
twice -- once to 5 GB, the 2nd time to 5.5 GB. In both cases, the OS sees
only 4.5GB, and the rest of the memory goes to waste.

it's all a supported Dell configuration, current BIOS, etc. They system is
supposed to support all of this. Any idea why i've hit this limit & how to
get past it?

thanks

 

[jlkj2]

let me add that the boot.ini has both of these switches specifiied: /PAE
/3GB.

should it have only /PAE?