SuperAMOLED at its finest, 6.2 inches of it
The Galaxy S9+ is equipped with a 6.2-inch SuperAMOLED display, Samsung’s own. Nothing’s changed in the numbers – it’s still in an 18.5:9 aspect (2.06:1) and resolution is 1,440×2,960px for a 521ppi density.
We measured a maximum brightness of 631nits in auto mode – that’s when the phone can push out more nits than you can get just by turning the slider all the way up, in which case you’d get something along the lines of 376nits. Both numbers are lower than on the S8+ (647 nits in auto, 442 in manual) and the Note8 (647/412), though the Auto figure is within a few percents. The smaller S9 has a few extra nits in auto (658), and it practically as bright as the Plus in manual (370).
The iPhone X can still go a little brighter, while other high-end OLEDs like the LG V30 and Huawei Mate 10 Pro are marginally dimmer than the S9+ in Auto. The Pixel 2 XL and OnePlus 5T max out some 200nits down.
|Display test||100% brightness|
|Black, cd/m2||White, cd/m2||Contrast ratio|
|Samsung Galaxy S9+||0||376||∞|
|Samsung Galaxy S9+ (Max Auto)||0||631||∞|
|Samsung Galaxy S8+||0||442||∞|
|Samsung Galaxy S8+ Max auto||0||647||∞|
|Samsung Galaxy Note8||0||412||∞|
|Samsung Galaxy Note8 (Max Auto)||0||647||∞|
|Apple iPhone X||0||679||∞|
|Apple iPhone 8 Plus (Standard)||0.392||530||1352|
|Apple iPhone 8 Plus (Max Auto)||0.471||621||1318|
|HTC U11+ (EU)||0.176||287||1631|
|Huawei Mate 10 Pro (vivid)||0||440||∞|
|Huawei Mate 10 Pro (max auto vivid)||0||623||∞|
|Google Pixel 2 XL||0||420||∞|
|LG V30 (Max Auto)||0.032||616||19250|
Sunlight legibility is excellent on the S9+, proper top-tier performance in our test. The S9 and the S8+ are marginally better in this respect, but the S9+ is superior to the Note8. The iPhone X remains unchallenged at the top of our chart.
Sunlight contrast ratio
Color accuracy is awesome if you know what you’re after and are willing to go into display settings and select the appropriate mode. Measured against an sRGB target color space, Basic mode yields an average DeltaE of 1.5, AMOLED Photo is faithful to AdobeRGB within an average DeltaE of 1.9, while AMOLED Cinema can reproduce the DCI-P3 color space with an average DeltaE of 1.7. Adaptive mode (the default setting) measured against an sRGB target will get you an average DeltaE of 4.8.
Samsung Galaxy S9+ battery life
The Galaxy S9+ packs a 3,500mAh battery – that number remains unchanged from the last generation. We’re firm supporters of the ‘moar is better’ philosophy when it comes to battery capacity, but if Samsung thinks 3,500mAh is enough – so be it. A year later, chipsets are more powerful while still made on a 10nm process, so there was a certain amount of anxiety on our part going into the battery tests.
It turns out we were wrong to worry. The Galaxy S9+ posted very similar results to the model it replaces. A 40-minute bump in video playback longevity sees that number verging on 17 hours. Web browsing over Wi-Fi depleted the S9+’s battery in a little over 11 hours, leaving the S8+ reloading pages for an hour more. If voice calls are your thing, the S9+ can do those over 3G for a full day and then some, an hour and a half more than the S8+.
Those numbers translate into an Endurance rating of 86 hours, 2h less overall than the S8+ and 3h less than the Note8. That said, the S9+ outlasts the Note8 in each of the three individual disciplines, only to lose its lead due to the Note’s lower standby consumption.
Even with the drop in the web browsing endurance, the S9+ remains one of the best performers in the field – only the Mate 10 Pro has an edge here (okay, with 15:21h the Mate is a league of its own). And then it’s only the Mate that comes close to the video playback endurance of the S9+.
In 30 minutes of charging, Samsung’s Adaptive fast charger will get the S9+’s battery from flat to 37%. It’s not blazing fast, and we’ve seen much more impressive numbers from, say, Huawei (58% of the larger 4,000mAh battery on the Mate 10 Pro in the same amount of time). The iPhone X, on the other hand, will be at only at 20% after a 30-minute charge from flat with the bundled adapter, so there’s that.
A couple of things should be noted. Number one, we had the Exynos version of the Galaxy S9+ for testing, and the Snapdragon variant has been known to post different results (typically not as good). Number two, the effect of the always on display on overall endurance will vary wildly depending on what percentage of the time the phone will spend in a pocket or purse. The AOD turns off in the dark or when its proximity sensor is covered. Our test takes into account the power consumption as it is while sitting on a desk during the day (when it’ll be on all the time) – so take our numbers as the worst case scenario.
It took a while, but we’re finally there – the Samsung Galaxy S9 and S9+ have stereo speakers. They’ve done it the Huawei way – the bottom-firing driver covers the low end of the spectrum and one of the channels in the stereo pair, while the earpiece is responsible for the other channel’s mids and highs.
While in landscape, the speakers switch according to orientation, so the earpiece acts as left channel while the earpiece is on the left, and right channel if you hold the phone the other way around. When in portrait, the right channel goes to the earpiece.
Not only is the sound stereo, but it’s also loud. The Galaxy S9+ placed in the Very good category in our three-pronged loudness test – marginally ahead of the iPhone X and marginally behind the LG V30 in total decibels. The output is clean and full-bodied, and a (strictly non-official) panel of two stereo speaker phone owners at the office ruled it superior to the Pixel 2 XL and the iPhone X in terms of quality.
|Speakerphone test||Voice, dB||Pink noise/ Music, dB||Ringing phone, dB||Overall score|
|Samsung Galaxy Note8||67.8||69.5||71.5||Good|
|Samsung Galaxy S8+||68.5||69.4||71.6||Good|
|Google Pixel 2 XL||66.2||70.4||78.2||Good|
|Apple iPhone X||68.9||74.0||76.2||Very Good|
|Samsung Galaxy S9+||68.4||74.0||80.1||Very Good|
|LG V30||66.9||72.3||84.5||Very Good|
|Huawei Mate 10 Pro||70.1||73.8||84.2||Excellent|
|Apple iPhone 8 Plus||76.0||74.6||79.0||Excellent|
|HTC U11+ (retail)||91.2||75.4||90.7||Excellent|
Solid audio quality
The Samsung Galaxy S9+ managed to replicate the performance of its smaller sibling when it came to audio output accuracy. The larger of the two flagships had the same perfectly clear output with an active external amplifier and negligible degradation with headphones.
Where the Galaxy S9+ didn’t quite match the Galaxy S9 is loudness – the Plus model was still above average, but it not really impressive. Then again that may not matter much depending on your headphones – for those sticking to lower-impedance ones the S9+ likely won’t be any different.
|Test||Frequency response||Noise level||Dynamic range||THD||IMD + Noise||Stereo crosstalk|
|Samsung Galaxy S9+||+0.01, -0.03||-92.6||92.5||0.0012||0.0076||-93.4|
|Samsung Galaxy S9+ (headphones)||+0.03, -0.03||-92.2||92.2||0.0017||0.042||-76.3|
|Samsung Galaxy S9||+0.01, -0.03||-93.4||93.5||0.0057||0.0074||-93.9|
|Samsung Galaxy S9 (headphones)||+0.02, -0.03||-93.0||92.9||0.0038||0.048||-75.5|
|Samsung Galaxy S8+||+0.01, -0.03||-92.1||92.1||0.0020||0.0086||-92.5|
|Samsung Galaxy S8+ (headphones)||+0.03, -0.03||-92.5||92.5||0.0024||0.046||-77.3|
|HTC U11||+0.05, -0.11||-94.1||94.1||0.0017||0.0067||-94.5|
|HTC U11 (headphones)||+0.05, -0.02||-93.7||93.8||0.0018||0.105||-53.7|
|LG V30||+0.02, -0.01||-93.2||93.1||0.0008||0.0069||-94.2|
|LG V30 (headphones)||+0.03, -0.02||-92.9||92.9||0.0057||0.051||-68.1|
Samsung Galaxy S9+ frequency response
You can learn more about the tested parameters and the whole testing process here.