Samsung Galaxy S5: Quad-core 2.5GHz Qualcomm Snapdragon 801 processor
Sony Xperia Z2: Quad-core 2.3GHz Qualcomm Snapdragon 801 processor
Much like with their displays, the Galaxy S5 and Xperia Z2 should be pretty evenly matched in performance, as both have Qualcomm's quad-core Snapdragon 801 processor. We've had some hands-on time with both devices, and both are impressively quick - so it will be hard to call a winner in this category, too. However, the Xperia Z2 does squeeze in more RAM, boasting 3GB of RAM compared to 2GB of RAM in the Galaxy S5.
Samsung Galaxy S5: Android 4.4.2 Kitkat, custom UI
Sony Xperia Z2: Android 4.4.2 Kitkat, custom UI
Both the Samsung Galaxy S5 and Sony Xperia Z2 arrive with the latest version of Google's Android mobile operating system, Android 4.4.2 Kitkat. Both devices also have a custom user interface (UI) from their respective manufacturer, skinning Google's stock UI and stuffing the handset full of custom applications.
Samsung has toned down its UI on the Galaxy S5 compared to the version on the Galaxy S4, and has also given it a lick of paint, making it more stripped down and easy to use, much like Apple's iOS 7 mobile operating system. However, it's still recognisable as a Samsung Galaxy S smartphone, featuring the same widget layout and the same applications on the homescreen.
Samsung has introduced some new features with its latest custom UI, though. Among these is My Magazine, a HTC Blinkfeed-style feed which is accessed by swiping left on the homescreen. Samsung has also included S Health 3.0, taking advantage of the smartphone's built-in sensors to monitor its user's fitness activities. There are several new camera features included, too, including Selective Focus, which allows the user to re-adjust the focus after an image has been taken.
Sony's custom UI, however, remains largely unchanged from the version found on last year's Xperia Z1. We've always found that Sony's UI is more usable than those of other smartphone makers, and while the handset still arrives covered in custom widgets and applications, it's a much cleaner design than that of others on the market. That said, we still find it a little overbearing compared to Google's vanilla Android UI.
The Sony Xperia Z2 is preloaded with Sony's Walkman and Playstation companion apps as seen on the Xperia Z1, as well as some new camera features and noise cancellation technology to help block out background sounds while listening to music.
Next: Cameras, battery and storage.