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Apple has yet to provide an official list of OS X 10.9 compatible Macs, but as we mentioned before regarding the first Mavericks Developer Preview, most Mac hardware that supports OS X Mountain Lion (10.8) should be able run OS X Mavericks (10.9) without any issue. This has been confirmed apparently by AppleInsider, who notes that Macs can even upgrade to Mavericks directly from OS X Snow Leopard 10.6.8 without having installed 10.7 or 10.8, assuming they meet the system requirements.
OS X Mavericks System Requirements
Macs must have a 64-bit Intel CPU and an advanced GPU to run OS X 10.9, additionally, at least 8GB of available disk space is required for installation. An internet connection is required to download OS X Mavericks.
OS X Mavericks Supported Hardware List
AppleInsider has provided the following list of what they say is Mavericks-compatible Mac hardware, it should be noted the initial list matches the supported list from 10.8 identically, and it could change by the time the final version ships.
iMac (Mid-2007 or later)
MacBook (13-inch Aluminum, Late 2008), (13-inch, Early 2009 or later)
MacBook Pro (13-inch, Mid-2009 or later), (15-inch, Mid/Late 2007 or later), (17-inch, Late 2007 or later)
MacBook Air (Late 2008 or later)
Mac Mini (Early 2009 or later)
Mac Pro (Early 2008 or later)
Xserve (Early 2009)
Features like Notification Syncing that rely on iOS-to-OS X integration and vice versa will require iOS 7 to be installed on the mobile devices to function, and obviously any iCloud specific features will require an Apple ID and internet connection to be able to use.
Additionally, features like OpenGL 4, accelerated scrolling, AirPlay Mirroring, AirDrop, PowerNap, and perhaps some of the newer features and system-level performance enhancements may have stricter system requirements, and generally tend to require newer Mac models for full support. Obviously any battery specific improvements to OS X 10.9 will require a portable Mac.
Because OS X Mavericks is currently in beta, it’s possible the system requirements will change before the fall release. Apple has yet to provide an official list of supported hardware or requirements for the next version of OS X, though they have shown what devices will be compatible with iOS 7.
