Last month, when we commented on the minimum requirements required for OS X Mountain Lion, we also said that AirPlay Mirroring requires a second generation Apple TV or higher and an iMac, Mac mini or MacBook Air (all from mid 2011 or newer ); or a MacBook Pro (from early 2011 or later). But after all, why only those younger ones?
Many bet that Apple was purposely leaving old Macs out, forcing users to buy new machines; some thought it could be something related to DRM technology (Digital Rights Management, or Copyright Gesture), present only on the latest Intel chips. But no, none of these theories were right. The technical answer, really.
According to the Cult of Mac, for AirPlay Mirroring to work I need a GPU (Graphics Processing Unit, or Graphic Processing Unit) capable of encoding H.264 videos without the need / help of the CPU (Central Processing Unit, or Central Processing Unit) and this happens only on the latest GPUs. "Without the support of physical hardware, mirroring would be CPU intensive, causing performance to reach levels never authorized by Apple," said Sid Keith, creator of AirParrot. For exactly the same reason, the feature is only compatible with the iPhone 4S and second- and third-generation iPads.
Mystery solved.
