Apple Watch Series 4 Performance Turns Heads by Matching Certain iPhones

It's a compact beast.

Apple emphatically flexed the A12 Bionic chip inside of the iPhone XS, XS Max, and XR at the rollout, but glossed over the S4 processor inside of the Apple Watch Series 4. But that’s not stopping the S4 from turning heads.

The company advertises the fourth-generation CPU to be “up to two times faster” than last year’s Series 3 processor. While there have been no tests of the S4’s capabilities, an iOS developer recently put it through various stress and found it packs the same punch as the 2015 iPhone model.

Steve Troughton-Smith developed a benchmarking app that uses “real time physics” and “physically-based metal rendering” to push the wearable to its limits. The Series 4 comfortably ran the program at 60 frames per second while only taking up 64 percent of its total CPU usage.

“The CPU has headroom to spare,” Smith tweeted. “What a beastly CPU. I need an iPhone 6s or newer to get similar performance out of an iPhone with this app.”

The S4 chip is a 64-bit, two-core processor compared to the 32-bit, two-core CPU of the Series 3. Both of these processors are called System in Package (SiP), which means they integrate every component needed to make the watches work into a single package.

This is distinct from the iPhone’s Bionic chips design, which is considered a System on a Chip (SoC). The key difference is that SoCs require a number of external components to make them function, while SiPs bundle together an entire system, perfect for compact devices like the Apple Watch.

The S4 is nowhere near as powerful as the A12 Bionic chip, which is capable of 5 trillion operations per second. iPhones also run a much higher resolution than the Series 4, which comes in a 42-millimeter face at a 312 by 390 resolution and a 44mm face with a 368 by 448 display. These specs are record-setting for an Apple Watch but the iPhone 6S has a resolution of 1,334 by 750 which would be much more demanding.

apple watch series 4 series 3
Apple Watch Series 4 and Series 3 go head-to-head. Via MacRumors.

While these under-the-hood improvements are quite noticeable during graphical tests like this, users may not necessarily see as big a difference in their daily use. MacRumors compared the Series 4 and Series 3’s speeds and found that the fourth-generation is just slightly quicker, which should be expected.

But raw processing power is by no means the only feature the Series 4 touts. Consumers will likely be drawn to its newly introduced health capabilities like its improved heart-monitoring technology, built-fall detection, and a host of fitness-friendly apps.