The /3GB switch allows Windows XP, 2003 Server, and 2000 Server to dedicate 3GB of memory address space to a 32-bit application, instead of the usual 2GB. Machines that already have 4 or more GB of physical memory cannot make use of the /3GB switch. In this case, use of the /3BG switch will limit an application to using a maximum of 3GB and will not make use of additional memory. For more information, see the Microsoft article in the Related Information.
ESRI has neither tested nor certified this configuration. ESRI does not support its use with ArcGIS or other ESRI products.