Catalyst 10.5 gives 120 Hz display support for ATI Radeon HD 4000 and HD 3000 series graphics processors (helpful with stereoscopic 3D), and ATI Overdrive enhancements which allow full control over ATI Radeon GPUs that are connected to multiple displays, eliminating a limitation.
Drivers & Support | GAME.AMD.COM
For so many users in different forums --- > 2D clocks are NOT in idle & idle temps are up
10.3 WHQL and 10.4a is still the best drivers IMO