Look at the heatsinks . the Anniversary heatsinks have very simple design compared to Pro4 .
Pro4:
- Premium Alloy Choke (Reduces 70% core loss compared to iron powder choke)
- NexFET™ MOSFET
http://www.asrock.com/mb/Intel/H97%20Pro4/
http://www.asrock.com/mb/Intel/H97%20Anniversary/
http://www.asrock.com/mb/Intel/H97M%20Pro4/