Two things can make smartphones fast: the speed of their data transfer, and the pure performance power of their processor. The former varies from carrier to carrier, market to market, and even quite possibly from building to building; but internal clock speed is a measure we can compare across phones.
Chipmakers constantly push the boundaries, which translates into liquid gameplay and buttery-smooth video playback, among other finessed touches of a faster phone. These top contenders will leave rivals in the dust. Read even more in CNET's quad-core smartphone shootout.
Samsung's Galaxy S4 powerhouse
Samsung Galaxy S4
Not only does Samsung's Galaxy S4 have the fastest gaming graphics of any other smartphone today, it's also in a dead heat as one of the top two fastest phones on the planet.
Sporting a 1.9GHz quad-core Qualcomm Snapdragon 600 processor in most markets (the phone is also made with an eight-core Samsung Exynos 5 Octa processor), the S4 has the highest capacity in terms of specs. In practice, it's about neck and neck with HTC's One (see below). Software processes, like boot-up time, take longer.
Sprint's HTC One is stunning, fast, and feature packed
Don't let the very slightly smaller capacity on HTC's stunning One fool you -- its 1.7GHz quad-core Qualcomm Snapdragon 600 processor is plenty smokin'. This phone boots up faster when you power it on and is faster than the S4 to put the camera app at your fingers. As a bonus, its LCD display also lights up more brightly for indoor and outdoor use.
The LG Optimus G Pro: Buy or pass?
LG Optimus G Pro
Packing the same 1.7GHz Snapdragon 600 quad-core chipset as the HTC One, LG's Optimus G Pro for AT&T is without a doubt a big, blazing-fast phone. The Android Jelly Bean handset can stand up to HTC and Samsung's upper crust when it comes to impressing us with diagnostic and real-world speed tests, though its 5.5-inch size will be simply too big for some.
The LG Nexus 4 arrives, but with no LTE
LG Nexus 4
Qualcomm's 1.5GHz quad-core Snapdragon S4 Pro ticker lights up the Nexus 4's fire. Compared with the new guard, this handset is notably slower when it comes to specs and diagnostics, though real-life tests still make this one of the quickest smartphones money can buy. The stock Android OS helps keep bloatware down, which keeps navigation and daily use smooth.
Huge Galaxy Note 2 has specs to spare
The industry's pre-eminent phablet, Samsung's Galaxy Note 2 was also one of the world's first quad-core beasts. The 5.5-inch screen warrants a high-capacity 1.6GHz quad-core processor; phone phreaks can geek out that it's one of the few to use Samsung's own Exynos processor across global regions.
The end result is a handset that isn't quite as fast as the others in terms of pure output, but which can hold its own nearly a year after its launch date. In the rapidly advancing smartphone world, that practically amounts to a lifetime.
The beefed up, quad-core HTC One X+
AT&T's HTC One X+ may be supplanted by the One now, but it in turn quickly topped the One X. The latter two both featured Nvidia's quad-core Tegra 3 processor, but the One X+ has the added benefit of LTE. Although new handsets are no longer on sale through AT&T, the One X+ is a fast phone in its own right.