Samsung Galaxy S6 vs S5 – should you upgrade?

While the Galaxy S5 was one of last year’s best phones, it felt like a slightly dull upgrade from the S4. Yes, it had some great tech, but the plastic build quality let it down. This year, Samsung has addressed that with two premium-build smartphones, the Samsung Galaxy S6 and its curved edge variant, the Galaxy S6 Edge. After reviewing them, we have to say that they’re the best Android handsets that we’ve ever seen.

However, that leaves two important questions: are they such an improvement that anyone with an S5 should upgrade now? And, are they so much better that the S5 is no longer worth bothering with, even though it’s now considerably cheaper? These are the answers we have for you, as we use all of the information we have from reviewing both handsets to help you make the right choice.

Design

Dimensions: There’s very little in it between the S6 models and last year’s S5. The standard S6 measures 143x71x6.8mm and weighs 138g, and the S6 Edge measures 142x70x7mm and weighs 132g; the S5 is a touch wider and a little thicker at 142x73x8.1mm and weighs a bit more at 145g. It’s not enough to make a huge difference and, if you were happy with the S5’s size, you’d be happy with the S6.

Materials: This is one area where Samsung has pulled out all of the stops and made the S6 a much better handset than its predecessor. Both phones use a metal chassis with a polished finish, which you can see around the edges of the handset. The front bezel and backplate have glass bonded to them, giving bright colours and a slightly translucent finish. The S6 is available in four colours and looks fantastic.

The S6 Edge takes the ‘basic’ models design and tweaks it to include that double-curved-edge display. While it gives the phone a look like no other, the curved display is far from essential, and the tweaks to use it don’t add a tremendous amount. It too comes in four colours. It’s the best-looking handset that Samsung has ever made.

While the Galaxy S5 isn’t a bad looking phone (it looks very similar to the S6, superficially), its plastic body lets it down slightly. It doesn’t quite feel like it’s a premium flagship phone. However, the old design has two advantages over the new one: it’s IP67 rated to withstand submersion in water (up to 1m deep) for 30 minutes, and the back is removable. This means that you can replace the battery or carry a spare if you know that you’ll be away from a charger for a long period.

Conclusion: The Galaxy S6 and S6 Edge look better and use premium materials. In terms of looks and build, there’s no competition. We prefer the curved S6 Edge, but the regular S6 looks great. That said, the new design isn’t IP67 rated and you can’t replace the battery, as you can with the S5. It all comes down to choosing what’s important to you: looks or battery/ruggedness.

Display

Screen size: Both the Galaxy S6 and the Galaxy S5 have 5.1in screens, with the new S6’s display protected by Gorilla Glass 4, and the old S5 using Gorilla Glass 3. Glass manufacturer Corning is convinced that the new glass is far tougher, you can see its comparisons here – Gorilla 3 vs. Gorilla 4. The S6 Edge also has a 5.1in screen, but the curved off edges mean it doesn’t look as big square-on.

Resolution: Both the Galaxy S6 and the S6 Edge have huge 2,560×1,440 resolutions, which amounts to a pretty amazing 577 pixels per inch, the highest figure we’ve ever seen. The Galaxy S5 has a 1,920×1,080 resolution, which is a still impressive 432 pixels per inch. With careful studying of test images, we found we could tell the difference between the two screens, but it makes no odds in day-to-day use.

Screen technology and quality: Both the S6 and S5 use Samsung’s AMOLED screen technology. Both phones also use the company’s latest diamond-shaped PenTile subpixel array, which provides better colour accuracy and brightness than previous models. Some people prefer LCD screens, but we like the superior contrast of an AMOLED. In short, they’re both great.

Conclusion: With more resolution, the S6 and S6 Edge have the advantage and look sharper, but the S5’s Full HD screen is still brilliant.

Performance

Processor and Graphics: In previous years Samsung has confusingly used different chipsets for its flagship phones in different regions. Here in the UK we got a Qualcomm SnapDragon 801-powered Galaxy S5. This quad-core chip has four cores that ran at up to 2.5GHz. It’s a 32-bit chip that was made with a 28nm manufacturing process (more on this shortly). All backed up with 2GB of RAM.

This year in the S6, we have Samsung’s own-brand 8-core chipset in all handsets: the Samsung Exynos 7420. This uses ARM’s clever big.LITTLE architecture with four low-power 1.5GHz Cortex-A53 cores for power efficiency and four high-power 2.1GHz Cortex-A57 cores for tougher tasks. The two sets of cores work seamlessly together to provide power and efficiency in one package. And you get more RAM too, with 3GB to run your apps in.

Better still the new chipset is manufactured with a more power-efficient 14nm process and is a 64-bit processor so that it can make the most of the new 64-bit friendly Android 5.0 operating system.

Benchmarks: The S6 handsets are undoubtedly faster than their predecessor. The new phones are the fastest Android devices we’ve ever seen across a wide range of benchmarks. In use, the new phones feel a litter snappier and can handle switching between multiple apps better. In our games testing with the Galaxy S6 and Galaxy S6 Edge, we got a score of 17fps in the GFXBench Manhattan test, compared to 11.7fps from the S5. It shows that the newer phone is far faster in tough graphics tests.

Battery: The S5’s larger battery and efficient AMOLED display made it one of the best performing handsets in our battery test roundup of 2014. It lasted an amazing 17h 30m in our video rundown test. We were surprised to discover that the S6 uses a smaller 2,550mAh (the Edge has a 2,600mAh battery): 250mAh less than last year’s model, which had a 2,6800mAh battery. The S6 managed 13h 37m in our tests, so it’s not quite up to last year’s standard; the S6 Edge lasted 15h 33m, so it was closer.

A bigger thing for some people is that the battery is not replaceable on the S6 or S6 Edge, while the S5’s removable back means that you can carry a spare, fully-charged battery with you – if you think you’d actually bother.

Conclusion: The new CPU in both S6 models is much faster than the old model, and it’s 64-bit, too, making the most of Android Lollipop. While battery life is still good in the new models, it’s not as good as last year and not being able to change batteries is a good reason for many people to stick with the S5.