Sprint and Clearwire formed a $14.5 billion joint venture a few weeks ago that will focus entirely on mobile WiMAX. The joint venture will be called Clearwire and includes investment from Google, Intel, Comcast, Time Warner, and Bright House Networks. According to the joint venture announcement, the new Clearwire expects to dramatically enhance the speed at which customers access the Internet. What does it mean to "dramatically enhance the speed of Internet access"? This article is the third in a five-part WiMAX tutorial series and focuses on WiMAX performance. The first part introduced WiMAX technology, applications and terminology. The second part described WiMAX services. Follow-on articles will discuss WiMAX security and devices.