A fast phone shouldn't just score well in benchmarks. It should deliver swift, everyday performance, too, whether it's opening a large file, gaming without lag or firing up its camera faster than you can say "cheese." We pitted six of the latest smartphones against each other in eight rounds of competition, and the Apple iPhone 6s came out on top, finishing first in six out of eight real-world tests and synthetic benchmarks.
The Samsung Galaxy S6, our previous winner, is our runner-up, turning in the fastest camera-open time and consistently placing second. The LG G4 dropped to third place. The biggest letdown continues to be the now very dated Nexus 6, which finished sixth overall and dead last in opening our PDF, camera-open and gaming tests. But a new Nexus 6P is on the way and we will update this comparison when it arrives.
iPhone 6s: Apple promised the A9 processor in the new iPhone would be significantly faster than it’s predecessor, with up to 70 percent faster CPU performance and 90 percent graphics, which means faster gameplay. And fast it is.
MORE: iPhone 6s Review
Samsung Galaxy S6: Samsung developed its own octa-core Exynos 7420 processor instead of opting for one of Qualcomm's CPUs. The S6 is also one of just two phones in this contest featuring advanced DDR4 memory (the other being the HTC One M9), and it features a faster storage format called UFS 2.0, which promises SSD-like speeds in a phone.
MORE: Samsung Galaxy S6
LG G4: With its Snapdragon 808 CPU, the G4 has difficulty matching the raw power of the S6, but it was the fastest to open its camera and snap a picture, and the second-fastest phone on our video-editing test and the Geekbench 3 performance benchmark.
MORE: LG G4 Review
HTC One M9: The HTC One M9 features Qualcomm's most powerful processor, the Snapdragon 810, and in theory should be able to keep up with the S6. Unfortunately, with the exception of graphics tests, the One M9 disappointed with weak performance.
MORE: HTC One M9 Review
Asus Zenfone 2: The Zenfone 2 is an interesting beast, featuring an Intel Atom Z3580 CPU and unmatched 4GB of RAM for an affordable $299. This phone finished a fairly strong third in our memory benchmark but didn't place better than that in any other test.
MORE: Asus Zenfone 2 Review
Google Nexus 6: As the ambassador for stock Android, the Nexus 6 should demonstrate the height of Google's smartphone experience, and while even its slightly older Snapdragon 805 SoC performed admirably, real-world results were disappointing, due to lethargic camera speeds, average Wi-Fi throughput and poor game performance.
Real-Word Performance Tests
PDF Load Time
To start, we wanted to see how long it would take each phone to open a whopper of a PDF (1.6GB). We measured the time it took to open the PDF (using Adobe Reader on Android and iOS) with a camera capable of recording slow-motion video at 240 fps. The iPhone 6s solidly beat the rest of the competition--and opened the PDF in just 82 milliseconds. Our previous fastest phone, the Galaxy 6, accomplished the same task in a now sluggish-looking 127 ms.
The Nexus 6, the only competitor running stock Lollipop, lagged far behind handsets running skinned versions of Google's OS with a laborious open time of 482 ms--that’s six times slower than the 6s.
Camera Load Time
Because you never know when you need to snap a photo, we wanted to test how long it takes to open the camera with 10 apps running in the background, including such popular programs as Facebook, Instagram and Twitter.
The top three phones separated themselves from the pack, with the LG G4 leading the way with a time of just 52.5 ms. The Galaxy S6 was close behind with 55.5 ms. The 6s landed in third place with 67.2 ms. These speeds were all in stark contrast to the Nexus 6, which sat in dead-last place with 128 ms — more than twice as slow as the G4, S6 and iPhone 6s.
Traditional graphics benchmarks don't necessarily provide a good measuring stick for gaming performance — they can be "gamed" by savvy phone manufacturers and often lack real-world context. That's why we used GameBench's new desktop tool to measure the average frame rate over a 3-minute racing session in the graphics-intensive Asphalt 8 game.
The iPhone 6s just barely squeaked past the Samsung Galaxy S6 by managing 31 frames per second to the S6’s 30 frames per second. The poor Google Nexus 6 came in well behind the rest of the pack, managing a tolerable 26 fps.
First up is Geekbench 3, which evaluates the CPU, RAM, GPU and storage, and combines them into a single score representing overall system performance. With a mark of 5,283, the Samsung Galaxy S6's octa-core Exynos 7420 SoC and speedy 3GB of DDR4 RAM crushed the competition. That's 20 percent faster than the second-place iPhone 6s, and 50 percent faster than the third-place LG G4.
Basemark OS II System
In Basemark OS II's system test, which performs multiple floating-point and integer calculations, among other computations, the 6s retained its lead. Interestingly, the Asus Zenfone 2 finished ahead of the HTC One M9 in the system test despite costing less than half the price.
Basemark OS II Memory
Next up was the Basemark OS II memory test, which evaluates NAND storage performance by reading and writing files of varying sizes. This tells us the theoretical max speed at which the phone can save and retrieve data from storage, which affects things such as app load times and local media playback.
The iPhone 6s once again finished ahead of the rest of the pack. It was more than 45 percent faster than the next closest phone, the LG G4. The G4 barely edged out the S6, despite the Samsung's more advanced UFS system (Universal Flash Storage), which has the ability to perform simultaneous reading and writing and looks to replace the older eMMC standard used in other phones.
3DMark Ice Storm Unlimited
3DMark’s Ice Storm Unlimited is a gaming benchmark that does much of the work “off screen” and allows us to more accurately test processors and GPUs without worrying about how they power the screens themselves. The iPhone 6s’s A9 processor, again, showed just how fast it was by speeding past all the other phones for first place.
Wi-Fi speeds are one aspect of performance that's often overlooked. A quick glance shows that every phone in our roundup features 802.11 ac capability, but our testing proves that not all Wi-Fi modems are created equal. Using the IxChariot networking benchmark, we sent packets of information to each phone from a blazing-fast Asus RT-AC87U router and measured the throughput.
From 15 feet away, the 6s delivered top speeds that were 30 percent faster than the next fastest phones, the S6 and HTC One M9. Those two, in turn, were more than 25 percent faster than the rest of the competition.. This can make a big difference in everyday use, whether you're downloading an app or movie, surfing the Web or streaming video.
Apple’s A9 chip is the real deal. The iPhone 6s took six out of eight rounds, and it often won by an enormous margin. For now, the iPhone 6s is the fastest phone in the world. If you’re willing to live in Apple’s ecosystem, then you’ll enjoy an extraordinarily fast device.
Co-written by Alex Cranz