Beefed-up hardware all around: CPU, storage, speaker, camera, charging, and fingerprint reader
Samsung has also upgraded the heart of the Galaxy, by using a 64-bit Exynos processor of its own making as well as beefing up the internal memory's speed and the amount of internal storage (now starting at 32GB, with 64GB and 128GB options to be available). I didn't have enough use of the S6 or S6 Edge to do speed tests, but both devices certainly felt snappy even with all the extra pixels to push around.
Samsung says it has improved the S6's speakers. They certainly sounded louder, but also distorted at high volumes, as an overdriven speaker often does.
The S6's cameras have been beefed up, with an f1.9 lens on both the front and back cameras, versus the S5's f2.4 aperture. That wider aperture should allow more light in, for improved image capture in low lighting. (The Note 4 introduced to the Galaxy line the f1.9 lens on the rear camera, but it kept the Note III's f2.2 lens on the front. The S6 uses the f1.9 lens in both locations.)
There are also more pixels in the rear camera's CCD versus the Galaxy S5: now 16 megapixels versus 8. (The Note 4 also has a 16-megapixel rear camera.) The increase in megapixels may or may not improve the images captured, as the camera software has more to do with image quality than raw pixels at this point.
I could not test the camera to see if it is as improved as Samsung says. But I was able to test two camera-related features. One is fast access to the camera, even when the S6 is asleep: Double-press the Home button to open the Camera app in less than a second. The other is the enhanced Camera app itself, which adds automatic HDR mode so the Galaxy S6 can decide when to take pictures in high-dynamic-range mode (after all, do you really know when to use it?).
Sure, the iPhone 6 has automatic HDR, but the iPhone 6 can't take HDR photos if the flash is used. The Galaxy S6 can.
The back of the S6 supports both competing induction charging standards (PMA Powermat and WPC Qi) -- used in the so-called wireless charging mats -- which is a breakthrough move users will very much appreciate.
Samsung claims the S6 has fast-charging circuitry, letting it charge to 50 percent capacity in 30 minutes when plugged into a power source. Samsung also claims that when using induction charging, the S6 can get to 20 percent charge in 30 minutes. I couldn't verify either claim in the brief time I had access to a device.
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