A little over ten days ago, we reported on what turned out to be a widely publicized issue with the new Apple iPhone 5s – it's accelerometer. It's been reported and confirmed beyond a shadow of doubt that the sensor is way off, though the exact cause split the community of unhappy Apple customers in two: some suggested that it's a software-side thing, while the rest argued it's the hardware.
According to RealityCap CEO and developer Eagle Jones, its the latter that had it right all along. As we noted in our previous report, Apple has gone ahead and switched its partner for the precision device from STMicroelectronics to Bosch, which would've been a-okay, but as it turns out, the new part actually appears inferior. Before you understand why, it's helpful to understand that accelerometers rely on two key measurements to showcase the level of their accuracy: bias and variance. The former describes the level of constant inaccuracy stemming from the hardware process, while the latter simply rates the consistency of an accelerometer's readings. Jones further explained this in an e-mail to Gizmodo:
A low bias, but high variance sensor might output: 9.85 9.75 9.81 9.90 9.79 9.77
A high bias, low variance sensor might have output like: 9.60 9.61 9.59 9.60 9.62 9.58 “
All fine and dandy, but it would appear that while variance for the two products is almost identical, the bias values differ greatly:
Meaning that iPhone 5s' equilibrium measurements can be off to a pretty wide margin if you're unlucky and get a more extreme case. What's more, Jones told Gizmodo that Apple could have actually compensated for this change with further factory calibration, but for whatever reason – they didn't. Luckily, according to Jones, this can still be salvaged, though the work-around and this whole issue will definitely serve to tarnish Apple's image of shipping products that just work from the onset:
What's most disappointing, though, is that we still haven't heard of Cupertino on the issue, which is probably smart on their end. That's not to say that it's not important – anything from gaming, to use of any tools and apps that take advantage of your iPhone 5s' accelerometer, down to the touted dedicated M7 chip can and will be affected.