Overloaded Database - Batch Updates vs Atomic/Single Updates
I agree with @gbn, can you share more details about what constitutes "load". 

First take a look at your server level wait types to get a feel for where your resource crunch points are. 

Also identify your poorest performing queries and those that are most frequently executed. These are where you should target your performance tuning efforts.

To get you started quickly, grab a copy of Glenn Berry's SQL Server Diagnostic Queries which contain a number of useful scripts that you can use.