Typically it's AMD or NVIDIA making the news about big improvements in performance via a new driver update but now it's Intel sending out a press release to announce that its new integrated graphics driver promises big performance gains as well as power efficiency gains:
A major graphics driver update for 4th generation Intel® Core™ processors with Intel® HD graphics, Iris™, and Iris Pro graphics has been released. It provides significant gaming performance improvements with Intel’s anti-aliasing feature CMAA (Conservative Morphological Anti-Aliasing, which helps smooth jagged edges in games) while enhancing battery life through newer power conservation techniques such as Adaptive Rendering Control. Experience up to 30% improvement in performance in certain OpenCL workloads and up to 10% improvement with certain games (see driver release notes for details). The new and enhanced graphics control panel offers additional media and display customization capabilities. Download the latest drivers for 32-bit and 64-bit.