Samsung Galaxy Note 4

The Samsung Galaxy Note 4 features a 2560×1440 Quad HD (“WQHD”) Super AMOLED 5.7-inch display with 2.5D damage-resistant Gorilla Glass 4 and provides a pixel density of 515 ppi (pixels-per-inch).

The Note 4 came in two variants, one powered by a 2.7 GHz quad-core Qualcomm Snapdragon 805 chipset with Adreno 420 GPU, the other powered by Samsung's ARMv8-A Exynos 7 Octa SoC with two clusters of four cores; four Cortex-A57 cores at 1.9 GHz, and four Cortex-A53 cores at 1.3 GHz, which is the same processor cluster sold for the Samsung Galaxy Note 3 in markets that mostly use or only have 3G (such as HSUPA and HSPA), and/or '2G', such as unaltered GSM and CDMA networks, similar to how the Galaxy Note 3 is sold. The phone has metal edges with a plastic, faux leather back.

Both devices that use 4G, LTE/LTE-A and Hybrid 4G-LTE Networks were only sold in Canada, Australia, the U.S., the United Kingdom (for some carriers), Sweden, Norway, Denmark, and South Korea, which have widespread 4G LTE Markets, or are solely 4G/LTE/LTE-A dependant such as Canada and Denmark, which did not use any 3G or older networks, except for HSUPA (Used as a fall back network should the signal strength be weak due to being underground or in the middle of a building), as well as HSPA+, which is a 3G network, though considered by some to be the Original 4G.[2][3][4] The GPU in charge in the Exynos chipset is the Mali-T760.[5]

The Chinese variant utilizes the TD-LTE and TD-SCDMA Plus Network.

Both variants came with 3 GB of LPDDR3 RAM and 32 GB of internal memory that can be expanded using MicroSD-XC cards.[6]

The memory card slot has been relocated to allow hot swapping without physical blockage by the battery.[7]

The Note 4's back-cover has a strong resemblance to the Note 3, with a faux leather texture (although without the simulated stitching). It has a new aluminum frame design, bearing resemblance from the Samsung Galaxy Alpha, but lacks an IP67 certification (water and dust resistance), which was present in Samsung's other flagship, the Galaxy S5, released half a year earlier.

Like the predecessors, the Note 4 also includes a stylus pen, branded S-Pen, incorporated into the design. Samsung touted new S-Pen features including tilt and rotation recognition[8] but these features were either not implemented or not supported.[9]

The Wacom digitizer has been upgraded to be able to distinguish between 2048 pressure sensitivity levels, twice as much as the predecessor.[10][11]

The Scrapbook feature introduced on the Galaxy Note 3 has been extended by a so-called Intelligent Selection feature that allows for optical character recognition of highlighted screen areas.[12][13]

The Note 4 also incorporates a user-removable 3,220mAh lithium-ion battery for the global model and a 3,000mAh non-removable lithium battery variant for the model sold in China. The global model is the last Samsung Mobile flagship to be equipped with user-replaceable battery.

The device is the first flagship phone by Samsung to support Qualcomm Quick Charge 2.0 for fast charging up to 15 Watts.[14]

The Note 4 features a USB 2.0 charging port instead of USB 3.0 (as was in the Note 3 and S5), in favor of a new feature called Fast Charge, which Samsung claims can charge the phone from 0% to 50% in about 30 minutes and from 0% to 100% in less than 100 minutes.

With the wireless charging rear cover accessory, which exists in both a plain rear cover form factor and an S View flip cover (or S Charger View) form factor, the battery can be charged wirelessly using Qi technology.[15][16]

The Galaxy Note 4 uniquely features an ultraviolet ray measurement sensor.[17][18]

Like the Galaxy S5, it is also equipped with heart-rate monitor, oximeter, among other, more common sensors (barometer, digital compass, front-facing proximity sensor, accelerometer, gyroscope). However, the Note 4 lacks the thermometer and hygrometer sensors which the Galaxy S4 and Galaxy Note 3 from 2013 were equipped with.[19]

The Air View feature is no longer useable with fingers like it is on the S4, Note 3, S5 and Alpha. However, it is still useable with the stylus.

The capacitive key on the left side of the home button is now a task key, whereas it has been a menu key for previous Galaxy Note series models. However, holding the task key for one second simulates a press of the menu key.[20]

Unlike its successor, the Galaxy Note 4 supports Mobile High-Definition Link (MHL), which can be used to connect the mobile phone to an HDMI display.[19]

Next to the wireless charging S View cover, another accessory for the device is the LED flip wallet (or LED dot case), which allows displaying the clock time through barely visible small pin holes on the front cover while closed.[21]

The S-View cover, a horizontal flip case with preview window, shares the functionality of the predecessor's, except the ability to create Action Memos (digital post-it notes) without unfolding the cover.

A flashlight shortcut, optional analogue clock designs (next to the default, digital clock), as well as the ability to record video, a shortcut to dial contacts (phone numbers) marked as favourite, and access to the heart rate monitor, all without opening the cover, have been added.[22][23]

The Samsung Galaxy Note 4 originally shipped with Google's mobile operating system, Android, specifically KitKat 4.4.4, with its user interface modified with Samsung's custom skin named TouchWiz Nature UX 3.0. The Note 4 contains most of the original Note's software features and functions, but also adds more significant upgrades from the predecessors, such as a new multitasking interface, expanded S-Pen functions, gestures, and refreshed menus and icons.

However, some Samsung Smart Screen and air gesture control functionality which was present on the Galaxy S4, Galaxy Note 3, Galaxy S5 and Galaxy Alpha, including Air Browse, Smart Pause, Smart Scroll and Air Call Accept, has been removed.[24][25]

The device can be updated to Android 5.0.1 Lollipop in many regions, bringing a new, refined UI, and new runtime. This version has been criticized for poor battery life. A further update to 5.1.1 is available, depending on the wireless carrier.

Most Note 4 devices can also be updated to Android 6.0.1 Marshmallow, bringing Android features like Android Doze (a feature introduced in Marshmallow that saves battery life) and greater control over app permissions to the device. The Note 4 TouchWiz UI was also evolved featuring the home screen icon pack known from the Galaxy S6 and also features new S Pen features known from the Galaxy Note 5 such as the new Air command menu design with custom shortcuts and Screen-off memo. However, the UI is still very similar to the previous UI and slightly similar to the S6 UI, but most of the TouchWiz UI resembles the original UI for the Note 4.

The new multitasking interface merges the Galaxy Note 3's “S-Pen window” feature and the split-screen feature known from the Galaxy Note 2, Galaxy S4, Galaxy Note 3 and Galaxy S5, into one feature. Applications (including the camera application[26]) can be transitioned from floating pop-up view to flexible split-screen view and vice versa, and can be put from normal into pop-up view by dragging diagonally from an upper corner.[27][28]

The Galaxy Note 4 uses a gallery software very similar to the one of the Galaxy S5, with support for functionality such as "Shot & More" and "Selective Focus". Additional camera modes can be downloaded from a store provided by Samsung.[29][30]

The gallery software is compatible with the Air View feature that allows previewing photos from albums when hovering the stylus above it.

User reports suggest that the Exif (meta data) viewer has been removed from Galaxy Note 4.[31][32]

Rear of Note 4 featuring Camera, Flash and Heart Rate Monitor

The main (rear-facing) camera is a 16 Megapixel (5312×2988) autofocus camera with 16:9 aspect ratio image sensor (Sony Exmor RS IMX240),[33] featuring Smart OIS (Optical Image Stabilization + software image stabilization), being the first mobile phone of the Samsung Galaxy Note series and the first original variant Samsung flagship phone to feature an optically stabilized rear camera.

It allows optically stabilized 4K (2160p) video recording at 30 fps, 1080p video recording with 30 fps and 60 fps (Smooth Motion) options and also 120 fps slow-motion video recording in 720p resolution. An option for 1440p video has been added in the camera software. Like the Galaxy S5, its rear camera supports high dynamic range (HDR) video recording with up to 1080p at 30fps.

While the camera software and user interface is largely inherited from the Galaxy S5, some changes have been made. Digital zoom is allowed up to eight times, twice as much as on the S5, Note 3 and earlier. The option to separately preserve the standard dynamic range version from high dynamic range (HDR) photographs and the Wi-Fi Direct remote viewfinder have been removed.[34]

The secondary (front-facing) camera is a 3.7 MP camera with an f1.9 aperture that can record 2560×1440 QHD videos and capture wide-angle pictures.

The Galaxy Note 4's front camera is the first front camera in any mobile phone that is able to record videos at 1440p (WQHD) resolution.

After the LG G3, the Galaxy Note 4 is the second mobile phone to be able to record optically stabilized 2160p (4K) video.[35]

Many users reported that their Snapdragon Note 4 phones failed to boot with the error of "mmc_read failed".[41] Some of them are reporting that the problem only occurs after the OTA Marshmallow update, but the other said that even without the update, they also got the same error. Related with this boot error, the same affected phones may freeze and eventually reboot after the screen locked, and in severe cases, reboot randomly during usage.[42] A workaround of preventing the CPU from going into deep sleep is available.[43] A class action lawsuit against Samsung about the eMMC problem in the United States is available.[44] Owners of a Note 4 exhibiting the defect may submit a claim evaluation with the certified legal counsel, Kantrowitz, Goldhamer & Graifman, P.C,[45] using the form on their website.

Batteries are being recalled for overheating risk from counterfeit batteries that were installed on devices refurbished by AT&T.[46]