4. Hardware compatibility
To run Windows 8 on your PC, you'll need a processor that's 1GHz or faster with support for PAE, NX, and SSE2. You'll also need a minimum of 1GB RAM for the 32-bit version or 2GB for the 64-bit version, along with 16GB (32-bit) or 20GB (64-bit) of space on your hard drive. For graphics processing, you'll need a Microsoft DirectX 9-compatible graphics device with a WDDM driver, Microsoft says.
Of course, that's the minimum. If you want to take advantage of Windows 8's touch features, obviously you'll need a multitouch device. To make the most of the software, you'll want considerably more than that.
Ubuntu's requirements, however, are much more modest: Canonical recommends 512MB of RAM, plus 5GB on the hard drive. You'll also find versions such as Lubuntu and Xubuntu for lower-spec machines. In short, if hardware is a constraining factor for you, Ubuntu is most likely the better choice.
5. Cloud integration
Starting with the launch of Ubuntu One in 2009, the cloud has played a key role in Ubuntu Linux for some time, enabling users to store files online and sync them among computers and mobile devices, as well as to stream audio and music from the cloud to mobile devices.
Ubuntu One works on Windows, OS X, iOS, and Android, as well as on Ubuntu. Users of Ubuntu Linux get 5GB of Ubuntu One storage for free; 20GB costs $30 per year.
Beginning with Ubuntu 12.10, the OS also integrates Web apps and online searches directly into the Unity desktop for a more seamless experience.
With Windows 8, the cloud is coming to the forefront of Microsoft's platform as well. For storage, Microsoft's SkyDrive offers users 7GB of space for free. If you need more than that, you can have an extra 20GB for $10, 50GB for $25, or 100GB for $50 annually.
Storage isn't the only benefit of the cloud, however. Beginning with this new release, the new Microsoft Account sign-in (formerly Live ID) lets you use a single username and password to establish common preferences among all the Windows-based hardware and services with which you work. The idea is to employ the cloud to connect your PCs, tablets, and smartphones through a common, user-specific experience.
Ubuntu doesn't fully compete with Windows in this regard, since it doesn't offer counterparts to Windows Phone 8 or Windows 8 RT that are tailored specifically to non-PC devices. However, Ubuntu for Android is in the works.
Although Windows RT apps run within a sandboxed environment for greater security, Windows 8 Pro desktop legacy apps have no equivalent. Instead, third-party software developers are left to their own devices to add security measures to their apps.
Windows 8 and Ubuntu Linux provide their own firewalls, however, as well as the option for full disk encryption.
Despite the fact that Windows 8 Pro offers some security improvements over Windows 7, the new OS still carries forward with the WinNT legacy kernel, which is at least partially responsible for the litany of security issues Windows has suffered over the years.