Again, you do not need /3gb for memory usage above 4GB. That's the /PAE switch and the AWE settings alone. With 16 GB memory, /3GB can be harmful as it reduces the number of page table entries you have and can result in memory issues for the OS.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability