Patrick Holland/CNET

I absolutely love the blocky, petite iPhone 5S. Second to the discontinued 4-inch iPhone SE, the 5S is one of the last truly small smartphones. But Apple giveth, and Apple taketh away. Despite discontinuing the iPhone 5S/SE form factor, the company gave iPhone 5S users a glorious gift: iOS 12.

In the past, if you had an old iPhone, updating to the latest operating system was a bit of a gamble. Software bugs might pop up or performance might slow down. But iOS 12 does the opposite. It's not a glitzy feature-packed update. Instead, it does a lot of behind-the-scene housekeeping that actually makes the iPhone 5S faster. It's a welcomed update and I definitely recommend downloading it.

Now playing: Watch this: iOS 12 beta speed test: How fast is it on older phones?

iPhone 5S with iOS 12 is fast

In 2013, the iPhone 5S launched with the A7 chip, the first 64-bit processor in any smartphone. Though it's 5 years old, that same processor allows the phone to run Apple's newest OS.

Even when iOS 12 was still in beta, we noticed improvements in speed, especially when it came to opening apps like Safari and Instagram. For example, if I wrote an iMessage in iOS 11, the keyboard took its time to appear. But in iOS 12, it takes about half a second less. Most of these speed improvements are fractions of a second. But like Richard Pryor's penny-shaving scheme in Superman 3, those fractions add up.

I should note that I didn't see huge improvements across all apps. Facebook, Maps and Weather showed little to no noticeable speed boosts. But unlike previous major iOS updates, the iPhone 5S never felt bogged down.

Below are actions where I observed speed improvements when running iOS 12:

iOS 12 vs. iOS 11 Action How much faster was iOS 12 than iOS 11 Opening Instagram 0.5 seconds Opening Mail 0.25 second Opening Safari (completely loading CNET.com) 3.5 seconds Opening Maps Identical Slide to open camera from lock screen 0.5 second Keyboard pops up (in Messages) 1 second Share sheet comes up (in Safari) 1 second Siri completing a request 0.5 second

Get new features for your iPhone 5S

There are a bunch of new features in iOS 12 available for younger iPhones, but some are left off from the 5S. You won't find Animoji, Memoji, AR app support, the Measure app or Message photo filters.

However, I did gain pretty much everything else including new Don't Disturb options in Control Center and Screen Time to view how much I used my phone and apps. Here are a few other notable additions to the iPhone 5S:

Siri Shortcuts

Shortcuts allow Siri to complete complex tasks with a single command. You can build your own or use Shortcuts someone else created. My favorite is one for converting videos to GIFs. I should warn you that some Shortcuts can take seconds to activate, leaving you staring impatiently at Siri's rainbow graphics flowing from one side of the screen to the other.

Notification grouping

It's not the sexiest feature, but grouping notifications by app is a huge step toward getting more out of that 4-inch screen. And there is something satisfying about dismissing a bunch of notifications with a single swipe from the lock screen.

Group FaceTime Calls

The good news is you can now talk to 32 of your iPhone-owning friends via FaceTime at once. The downside is that the iPhone 5S only supports audio Group FaceTime calls. I tried Group FaceTime call with 28 people and it worked, albeit it was chaotic with that many people talking.

Customize Control Center

I like being able to customize what's in the Control Center Panel. I added buttons for screen recording, QR scans, the magnifier and Apple Wallet.

New battery graphs

No matter how good this software upgrade is, there's no getting around the fact that I'm using a phone with a 5-year-old battery. So I welcome any and all information I can get about what's draining it. Under the battery menu in Settings, there is a graph showing your phone's battery level since the last charge. Another graph shows off activity.

CNET

Consider this before upgrading

Despite my overwhelmingly positive time with iOS 12 on my iPhone 5S, there are a couple things to be wary about before you upgrade.

Whether it's via iCloud or just though iTunes, be sure to backup your data. Hopefully you already backup your phone, but in case it's been awhile, take the time to protect your information before taking the leap to iOS 12.

Next, check your storage. Your phone needs roughly 2GB of space to install iOS 12. To do this, go into Settings > General > Storage & iCloud Usage. There you can view how much storage your phone has and what's using it. If you need more room, there are a bunch of things you can remove to open up space.

Last, despite iOS 12 speeding up things on your phone, it does take time to download and install. I recommend starting the process before you go to bed, or while you're doing something else like laundry or cleaning the house. You can also load iOS 12 onto your phone via iTunes which is much faster.

Once you clear all these hurdles and get iOS 12 on your phone, enjoy your new-ish tiny phone that Apple managed to keep afloat after so many years.