Apple imbued the iPhone 5S with not one, but two, chips that it thinks made the 5S one of the powerful phones on the market in 2013. A lot has changed since its launch, and there's now a raft of newer handsets packing in more power - but the 5S is no slouch.
It's almost insane to think of the power running under the hood here, and there's no doubt that it's given things a real performance boost - that said, it's not realised the potential of that chip in the way other phone manufacturers have, although it still impressive when it comes to graphics reproduction and similar tasks.
The A7 chip from Apple inside the iPhone 5S is an interesting concept: not only does it bring a huge boost in power, but it offers 64-bit computing too.
To most people that label will mean nothing more than wondering whether this means their phone is as powerful as a Nintendo 64 – in reality, it's actually a pretty important move for the company.
Simply put, a 64-bit chip allows for more powerful processing and a greater amount of power to be plugged through the phone for most tasks. It will tolerate a greater amount of RAM in the future too.
The thing is, it doesn't really mean much to the consumer right now. There are some noticeable elements that take advantage, with the camera being much faster and able to handle so much more smoothly. And I'm willing to bet the Touch ID sensor is going to need a hefty whack of power to enable such tight security on the phone.
Beyond that though, you're not going to notice much in the way of an improved experience, and that's not because this phone is slow, it's because the iPhone is already a slick and fast beast.
The majority of top-end phones coming out this year are going to be equipped with 64-bit chips because of the extra power it affords, and the iPhone 5S helped lead the way.
It gave Apple the opportunity to talk about a chip that's still one of the most powerful around, and which is becoming ever-more useful as apps and software evolve to catch up with it. The iPhone 5S was Apple getting its iPhone range ready for the next generation of devices and apps.
But what does it all mean for you, the consumer? Well, put simply, you still get a serious level of CPU power without compromising too much on battery life - although the latter part still isn't great.
It was partly a marketing exercise, and partly Apple future-proofing itself, allowing its phones to add in new layers of security and providing developers with the tools to make even better apps. That future-proofing means the iPhone 5S is still a decent-value proposition in 2015.
There's another cheeky little chip under the hood that sits alongside the A7 main unit: the M7 chip, which is there to make the iPhone 5S a rival to the likes of the Nike Fuelband and the Jawbone Up.
It allows the main CPU to snooze while it tracks the motion of the phone, through the accelerometer, gyrometer and compass.
This means that it will know when you're jogging or when you're in the car, and can take that information and store it without needing to drain the battery by having the main CPU chugging away.
It can even retrofit the data to apps that you download at a later date, meaning any M7-enabled app that uses the new CoreMotion API will be able to give you information on recent training.
It will also seamlessly slip from walking to driving navigation on Apple Maps, which is a nifty extra, taking another hassle out of life, and especially useful for keeping drivers safe behind the wheel.
We're seeing the benefit of what's on offer with the M7 chip now that Apple has released the Health app. It's a comprehensive record of your activity and a place to store important health data, and it ties in with all the top fitness apps and wearables.
As with the Health app, other apps should be able to plug into the M7 chip just as easily as the M8 upgrade in the newest iPhones.