HTC One M9 review: Much hyped, but a disappointing update

Specs and performance

All the M9's horsepower is provided by this year’s top-end Qualcomm chip, the octa-core Snapdragon 810, which comprises twin quad-core CPUs operating at a frequency of 2GHz and 1.5GHz respectively. Graphics are dealt with by an Adreno 430 GPU, and there's 3GB of RAM and 32GB of storage (expandable by up to 128GB via microSD card). In terms of connectivity, there are no surprises, with support for 4G, 802.11ac Wi-Fi, Bluetooth 4 and NFC. You don’t get wireless charging, though.

It's a strong line-up and results in the benchmarks were highly impressive. In the GFXBench T-Rex HD (onscreen) test, the M9 returned a frame rate of 49fps – no Android phone we've tested so far matches that. It's as fast as the iPhone 6 and 6 Plus in these tests. Likewise, in Geekbench 3, single- and multi-core scores of 838 and 3,677 soundly trounce all comers. And the HTC One M9 remains among the fastest phones I've tested, despite the appearance of a number of strong rivals since its launch.

Even burdened with the extra weight of HTC's Sense 7 launcher software, the phone feels very responsive indeed. Everyday tasks such as browsing Google Maps or hefty web pages – even updating apps while playing games – don't tax the HTC One M9 unduly, and it will play and record 4K video without breaking sweat. Despite widespread reports of overheating, I can't say I had a problem: the M9 gets warm when playing games, and warmer still when running benchmarks, but it never reaches truly uncomfortable levels.

As for battery life, HTC has boosted the capacity over the M8 by 240mAh, to 2,840mAh. We'd hoped that stamina would be improved, especially with the Snapdragon 810 SoC moving to 20nm. If anything, though, battery life has taken a hit with the M9. Standby battery life looks to be better – streaming a podcast over 4G using the SoundCloud app ate capacity at a rate of 2.61% per hour versus 3.8% for the M8 – but with the screen on, video playback consumed battery at a faster rate of 9.7%, compared with 6.5%.

In real-world use, I found the M9 was equally disappointing. With even moderate use, I regularly needed to recharge before the end of the day, when I'd started it with a full 100% on the gauge. In contrast, the HTC One M8 regularly lasted into a second day of use.

On the plus side, the HTC One M9 now supports Quick Charge, which does mitigate the battery-life issue somewhat, delivering a good wallop of charge in ten minutes or so, and a full charge in less than two hours. Alas, HTC doesn't supply a compatible charger in the box – just a bog-standard 7.5W USB charger.

Display and audio

Flying in the face of flagship smartphone trends, the HTC One M9 has a mere 5in Full HD, 1,080 x 1,920 display. Although this sounds behind the times, it's perfectly sharp at normal viewing distances. It's very bright as well, reaching 462cd/m2 at maximum brightness, so readability in bright sunshine won't be an issue. Contrast is absolutely superb at 1,310:1, and HTC has changed the axis of the polarised layer in the screen so that it doesn't black out in portrait mode.

In terms of its colour performance, however, the Super LCD 3 technology used in the panel trails significantly behind its rivals. In testing, the panel was able to reproduce 87.2% of the sRGB colour gamut, which is decent, but not nearly as good as the AMOLED displays on Samsung's flagships are able to reproduce. Colour accuracy was also less than ideal, with the M9 recording an average Delta E of 3.17 and a maximum of 7.6. As a result colours looked a little off, particularly the reds, which are muddier than they ought to be.

The front-facing BoomSound speakers above and below the screen, however, are unequivocally a success. For speakerphone conversations, YouTube how-to videos and streaming radio, the HTC One M9 gives every other smartphone brand an audio drubbing, and if you ramp up the ringtone volume, there's absolutely no danger of missing a call.

With the speakers off and the phone clamped to your ear, the HTC also put in a first-class performance, with calls coming through loud and clear with no sign of distortion.