Which of the big three is the smartest of the smartphones?

The smartphone war is heating up again, with two new contenders in the market. But is there a clear winner? We put the latest Samsung Galaxy S5 and HTC One M8 against Apple's iPhone 5s to see.

Display
There's a growing trend in smartphones for bigger displays as we increasingly rely on our phones for both work and play. However, that's one the iPhone has largely resisted. In spite of a bump to the 4-inch display that the iPhone 5 brought, the Apple device remains the smallest of the three phones here.

However, it’s not all about size, and the iPhone 5s is definitely up there with the best when it comes to crisp, clear displays. Apple has its own designation for this – Retina – but it’s a proprietary term. What really matters is that the display looks great for both text and photos.

However, in our opinion, the Galaxy S5 outclasses the iPhone 5s. Not only does it cram more pixels per inch into the display, at 436ppi compared with the iPhone’s 326, its full HD screen is also Super AMOLED. It’s bright, vivid and crisp – exactly what you want from your smartphone.

The extra screen space may make the phone a little bigger, but once you’ve experienced it, it’s difficult to look at the 4-inch display as anything but a bit dated.

There’s very little difference in size between the M8 and the S5 – a mere 0.1 inch – but the M8 has a super LCD3 screen with a pixel density of 441ppi. Again, it’s bright and crisp.

This one is a toss up between the M8 and the S5, but we think Samsung just edges it.

Performance
This is where things get a bit tricky. The iPhone 5s, when it launched, made a big deal of its 64-bit processor. And it is a big deal – but probably more important in the future than right now.

Of the three, the Samsung phone looks like it has the faster processor, with a 2.5Ghz Snapdragon processor compared with the 2.3Ghz in the M8.

The iPhone 5s clocks in at 1.3Ghz, but its performance far exceeds the figures. So don’t get hung up on clock speeds too much. The real test is how fast it performs tasks, and all three are zippy regardless of what you throw at them.

Also worth mentioning is the coprocessor, which both Apple and HTC have implemented for their phones. The iPhone’s M7 coprocessor is designed to be low powered and can be used for sensors to work with fitness apps, for example. Ditto for the HTC, although the iPhone gets the credit for doing it first.

It’s a close run thing here, with very little to choose between the three.

Camera
When it comes to the megapixel count, the Galaxy S5 wins out on numbers alone. Its main camera weighs in at 16 megapixels and shoots video at 720p. That compares with 8 megapixels for the iPhone 5s and 5 megapixels for the HTC One M8.

However, this doesn’t tell the full story. Sensor size and pixel size matter, and in that regard, the Galaxy falls behind a little. Of the three, the Galaxy has the smallest pixels, Apple comes in second and HTC has the biggest, enabling better quality low-light shots.

Sensor size also comes into play here. The sensor will record light to create your digital photograph; the size of that sensor will determine how much light can be recorded, so the bigger your sensor, the more light you can record.

The front facing camera is a different story: the Galaxy S5 camera is only 2 megapixels and 720p resolution, versus the HTC One M8’s 5 megapixels at 1980 resolution. The iPhone 5s, meanwhile has a 1.2 megapixel camera, which pales in comparison.

Flash-wise, the HTC and the iPhone both opt for the dual LED flash, which tries to replicate light more naturally by mixing different tone flashes.

All of the phones offer extra features for the camera, from slow motion modes to the HTC Duo camera, which will allow you to capture extra information such as depth of field. That means you can refocus after you take the shot.

The winner here will be down to personal preference. Selfie fan? Go for the HTC One. The rest is a toss-up, with the iPhone and HTC One M8 battling it out.

The iPhone 5s edged it in terms of quality for us, even though technically the M8 had better low light performance – the resulting photos seemed a little too bright at times, losing some of the detail.

Power
For some, the Galaxy will be the hands down winner here. It delivers slightly more talk time than the HTC One and roughly double the iPhone 5s, but falls behind the M8 on standby time. Plus, with the power saving modes that both phones promise, you can eke out the battery that little bit longer.

Really, it will all depend on what you use your phone most for. However, the battery on the S5 is removable, which means you won’t have to deal with the embedded batteries of the HTC One and the iPhone 5s. Should battery life go to hell on your handset, it’s easy to solve. Ditto for a back up battery, if you’re so inclined.

Capacity
This is where the two Android phones have the edge over the iPhone. The iPhone 5s, like the rest of Apple's devices, comes in three storage sizes: 16GB, 32GB and 64GB. What you see is what you get, and when it's full, get deleting or turn to cloud storage such as iCloud or Dropbox.

The HTC One and the Galaxy S5 both make use of the MicroSD card slot, so while they have less memory out of the box – 16 and 32GB versions for both – it’s expandable up to 128GB.

That memory card is also transferable, so when you change phone you can simply pop it out and use it in your next phone. Buying a 16GB or 32GB memory card is also significantly less expensive than the price difference between the iPhone models.

One thing to note is that the iPhone’s operating system tends to suck up less memory than the preinstalled Android OS on both the HTC and the Samsung. However, that inflexibility is a deal breaker for some.

Design
HTC has gone for a unibody aluminium frame, with the iPhone sticking with its tried and tested gorilla Glass, aluminium combo. While it's considered more premium, the M8 is the weightier of the two.

Meanwhile, Galaxy S5 has stuck with the plastic shell, but made it water resistant. It's not essential, but it's certainly a nice extra and, with Sony making its premium smartphones a little tougher these days, it's becoming desirable to have a smartphone that will survive a bit of water.

On looks alone, the M8 certainly has the edge. The iPhone’s current design is starting to look a little tired, while the perforated rear cover on the S5 has had a mixed response.

This round goes to HTC.

Extras
Both the Galaxy S5 and the iPhone 5s have fingerprint scanners for security and shopping. Samsung has gone one step further and signed up with Paypal to allow the technology to be used for shopping with retailers that accept payments through its mobile app.

The iPhone’s Touch ID, however, is useful not only for logging in without a password, but also for buying apps from the App Store, although it will periodically ask you for the password too. On a day-to-day basis, that’s arguably more useful.

The heart rate monitor built into the S5 is probably a bit of a novelty item, but fitness focused users may see it as a plus.

The HTC One M8, meanwhile has opted for things like touch and tap gestures to make viewing your notifications or accessing certain phone functions that bit easier. If you want to shell out a little extra, the Dot View cover gives you protection with a retro twist, plus access to some of your phone’s crucial features.

Apple’s Touch ID may have seemed like a bit of a gimmick, but of the three phones’ extra features, it’s probably the one that will get the most use – for now.

Verdict
Diehard Apple fans probably won't be persuaded that a move to Android would be in their best interests.

The Samsung Galaxy S5 came out on top – just – but the HTC One M8 is certainly worth consideration. The truth is these days there is very little between the top three, which is both a help and a hindrance for consumers.