A benchmark study comparing the relative performance of six EJB design idioms.
You may be surprised to find that a flawed architecture of your EJB application
could lead to performance 120 times slower than that possible with an appropriate
architecture. If you are having performance troubles with your J2EE app,
then check this out!

http://www.urbancode.com/research/default.jsp

Idioms used in the benchmark
The design idioms covered by the benchmark are:

1. Fine Grained Entity Bean (FGE)
often used by beginners to Enterprise Java Beans
2. Coarse Grained Entity Bean (CGE)
the best performing Entity Bean idiom typically used in practice
3. Coarse Grained Container Managed Entity Bean (CGCME)
touted as faster then Bean Managed Persistent Entity Beans
4. Optimized Entity Bean (OE)
the best performing contender that still uses Entity Beans
5. Session over Entity Bean (SE)
typically advanced as a "best practice" in trade media
6. Coarse Grained Session Beans (CGS)
the proposed best performer