Problems reading SD card Windows Phone. Choosing a Micro SD Card for Your Lumia Reasons for Reading a Flash Drive Error

The range of "Windows backgrounds" has been expanded with the following models. Four variants of the Lumia 640: single SIM and 3G, single SIM and LTE networks, with two slots for SIM-cards and support for 3G networks, with two slots and LTE. Also presented to the public were four variants of the Lumia 640 XL with a similar combination of distinctive features. The younger model Lumia 640 is equipped with a 5 "screen, while the Lumia 640 XL has a slightly larger screen - 5.7". Considering that all smartphones will be sold at the same time, and the options with one and two SIM-cards will have the same price, then the question involuntarily arises: what, in fact, were Microsoft marketers thinking? The Lumia lineup is already overflowing with devices, and you can only figure out how one of them differs from the other if you read the lists of characteristics and compare them line by line. The release of four pairs of smartphones with the same price and the only difference in the number of SIM card slots does not make the process of choosing a mobile companion any easier. Why market identical smartphones with support for one or two SIM card slots with the same price tags at all? After all, it is clear that, all other things being equal, buyers will give preference to models with support for two SIM-cards.

Be that as it may, at the time of preparation of the review on the Microsoft website there was information about only four variants of the smartphone: 640 LTE, 640 DS LTE, 640 DS 3G and 640 XL DS 3G. Further in the text of the review, the abbreviation "DS" means support for two SIM-cards. For all variants of the smartphone, several body colors are available: white, black, red and blue. Some of them were in stock, others were available by reservation only.

The basis for the devices of the Lumia 640 family is the SoC Qualcomm Snapdragon 400, all smartphones are equipped with 1 GB of RAM 8 GB of flash memory. The display type is the same for all models (the diagonal is different), but the main cameras of the 640 and 640 XL are different: 8 Mp and 13 Mp matrices, f / 2.2 and f / 2.0 optics, respectively. The front cameras also differ: a 5MP Full HD wide-angle camera for the Lumia 640 XL and 0.9MP HD for the Lumia 640. Naturally, the larger 640 XL has a more powerful battery: 3000 mAh versus 2500 mAh. And one more difference: models with LTE support are also equipped with an NFC module.

The hero of this review was a smartphone in the Lumia 640 DS 3G variant.

Features of smartphones Microsoft Lumia 640

• SoC Qualcomm Snapdragon 400 MSM8926, 1.2 GHz, 4 cores ARM Cortex-A7
• GPU Adreno 305
• Operating system Microsoft Windows Phone 8.1 Update 2, Lumia Denim package
• 5 ″ touch display, IPS, ClearBlack, 1280 × 720, capacitive, multitouch, Corning Gorilla Glass 3
• RAM 1 GB
• Internal memory 8 GB
• Nokia Lumia 640 3G model: 2G GSM (850, 900, 1800, 1900 MHz), 3G WCDMA (850, 900, 1900, 2100 MHz)
• Nokia Lumia 640 LTE model: 2G GSM (850, 900, 1800, 1900 MHz), 3G WCDMA (850, 900, 1700, 1900, 2100 MHz), 4G / LTE (bands 1, 2, 3, 4, 5, 7, 8, 12, 17, 20, 28)
• Data transmission GPRS, EDGE, HSPA + (up to 42 Mbps), LTE (up to 150 Mbps)
• Wi-Fi 802.11b / g / n, Bluetooth 4.0, NFC
• GPS / Glonass / BeiDou, accelerometer, magnetometer (compass), gyroscope, proximity sensor, light sensor
• FM radio
• Cameras: main 8 megapixel (autofocus, flash), additional 0.9 megapixel
• Removable battery 2500 mAh
• Dimensions 141.3 x 72.2 x 8.8mm
• Weight 145 g

For comparison, the table shows the characteristics of several of the latest Nokia models in the version with LTE support.

	Microsoft Lumia 640	Nokia Lumia 735	Nokia Lumia 830	Nokia Lumia 930	Nokia Lumia 1520
Screen	5 ″, IPS	4.7 ″, AMOLED	5 ″, IPS	5 ″, AMOLED	6 ″, IPS
Permission	1280 × 720, 294 ppi	1280 × 720, 312 ppi	1280 × 720, 294 ppi	1920 × 1080, 441 ppi	1920 × 1080, 367 ppi
SoC	Qualcomm Snapdragon 400 MSM8926 @ 1.2GHz (4x ARM Cortex-A7)			Qualcomm Snapdragon 800 @ 2.2 GHz (4 core Krait 400)
GPU	Adreno 305			Adreno 330
RAM	1 GB	1 GB	1 GB	2 GB	2 GB
Flash memory	8 GB	8 GB	16 GB	32 GB	32 GB
Memory card support	there is	there is	there is	No	there is
Operating system*	Windows Phone 8.1				Windows Phone 8
SIM format **	Micro-SIM	Nano-SIM
Communications		2G / 3G / 4G, Wi-Fi 802.11b / g / n, Bluetooth, NFC	2G / 3G / 4G, Wi-Fi 802.11a / b / g / n, Bluetooth, NFC		2G / 3G / 4G, Wi-Fi 802.11a / b / g / n / ac, Bluetooth, NFC
Battery	removable, 2500 mAh	removable, 2220 mAh	removable, 2200 mAh	non-removable, 2420 mAh	non-removable, 3400 mAh
Cameras	rear (8 MP; 1080p video), front (0.9 MP)	rear (6.7 MP; 1080p video), front (5 MP)	rear (10 MP; 1080p video), front (0.9 MP)		rear (20 (5) Mp; video 1080p), front (1.2 Mp)
Dimensions and weight	141 x 72 x 8.8mm, 145g	135 x 69 x 8.9 mm, 134 g	139 x 71 x 8.5mm, 150g	137 x 71 x 9.8 mm, 167 g	163 x 86 x 10.6 mm, 209 grams
Average price***	T-12206544	T-11030519	T-11030194	T-10771306	T-10548283
Nokia Lumia 640 DS LTE Retail Offers	L-12206544-10

* OS version is indicated at the time the device appeared on the market
** The most common SIM card formats are described in a separate article
*** average cost at the time of reading the article

Equipment

The smartphone comes in the traditional packaging for the current generation of Lumia devices. The construction is assembled from two boxes, the inner part fits into the outer cover. There is not much information on the parameters of the smartphone on the packaging, all of it is presented in the form of a few icons. Some details about the characteristics of a particular smartphone model can be found from the text and abbreviations from the sticker glued to the package.

The mobile computer that visited the editorial office only had a charger and documentation. Based on information from Microsoft's website, Lumia 640 buyers will receive just such a modest set of accessories.

Appearance and usability

There are several typical skin options for Lumia smartphones. The first group includes strict rectangular (in plan) devices with chopped sharp edges. Devices of the second group also differ in faces that intersect strictly at an angle of 90 degrees, but their body is made of plastic, not metal. Finally, the third extensive group includes models with rounded, smoothed body contours and smoothly merging edges. Most of the third category are also made of plastic. Obviously, cutting and turning metal at right angles is still easier than shaping it round or curving.

The current hero of the review belongs to the third category of Lumia smartphones. Smooth body lines and colored plastic give the Lumia 640 a somewhat frivolous look, but such is the long-standing trend of Nokia / Microsoft designers. They love cheerful and cheerful tones in their devices, and we can only praise them for that. For lovers of austere style, there is a black and white back panel.

The Lumia 640 looks good at first glance, but the devil is in the details. And the longer you work with your smartphone, the more, unfortunately, you discover such frustrating moments.

The main, main, almost ultimatum design flaw of the Lumia 640 is extremely slippery plastic. Perhaps the current hero of the review is the most "unstoppable" in the bad sense of the word smartphone from those that have been in my hands. The lacquered back and sides of the Lumia 640 transform the smartphone into a bar of soap. Nothing helps - neither a sufficiently large width of the edges, nor a significant surface area of ​​the rear panel; the smartphone still strives to slip out of hand every now and then. There can be no question of using the device in transport, and even more so doing something there with one hand: one extra push - and the Lumia 640 will go out of the palm towards the center of the Earth. What made Microsoft designers choose such a material for the body of the review hero is understandable, but what allowed engineers to agree with them is difficult. Most Lumias use much less slippery soft-touch plastic, which feels like rubber to the touch. However, judging by the appearance of the recently announced Lumia 435, slippery plastic is a long-term trend in the creativity of Microsoft developers. It is sad. Well, in order to finally close the topic of the plastic back of the Lumia 640, I note that, as befits a lacquered surface, it perfectly collects fingerprints, traces of touches and scratches.

Given the above, it would be possible not to dwell in detail on how the smartphone lies in the palm of your hand. But if we abstract from the lacquer plastic or imagine that the owner of a mobile computer has a very rough skin or the surface of a smartphone is covered with a layer of dirt, then the following should be noted: in terms of dimensions, the Lumia 640 fits perfectly into a medium-sized palm. The smartphone has to be held firmly, and the fingers have something to catch on - the wide side edges help. When working with a smartphone, the power button is located just under the thumb of the right hand. The relatively light weight of the mobile computer does not cause discomfort or fatigue.

It is difficult to operate the Lumia 640 with one hand, but if you really want to, you can. The main obstacle in this is not a large display, but, as already mentioned, slippery plastic. The mobile computer fits in the pocket of trousers and shirt without problems.

There are no complaints about the quality of materials and workmanship of the Lumia 640. Plastic does not look cheap, does not crunch or creak, the back panel of the smartphone does not bend, backlash of parts and extraneous sounds are absent when shaking.

Moving on to the next unpleasant aspect of the Lumia 640's look and feel - the wide gap for the phone speaker. When the smartphone was in the editorial office, a certain amount of dust had already accumulated in this deep container. Over time, there will be even more of it, if you do not pay due attention to its cleaning. But the earpiece hole isn't the only dust and dirt collector on the Lumia 640's bezel.

The same depth, but much smaller hole is provided for the microphone, which is located at the bottom of the screen. It will be really difficult to clean anything out of it. This "deep" list ends with a gap between the protective glass of the display and its plastic rim.

The entire front panel of the Lumia 640 is made of Corning Gorilla Glass 3. Beneath it are the display, lens front camera, lighting and proximity sensors. Lumia 640 does not have dedicated touch buttons for operating the system, they are replaced by virtual counterparts.

The back panel of the smartphone covers its entire body, overlapping all the side edges. This design of a mobile computer is also called a "boat". The construction is sturdy, but it can be very inconvenient if you need to access the battery compartment. The Lumia 640 is one such case. In order to more or less quickly detach the back panel, you have to press quite hard on the lens of the main camera, holding the smartphone by the upper edge of the case. No nail recesses or other aids are provided. We just press on the lens, the body is squeezed out, a millimeter of plastic appears, we hook it with our fingernail and separate the two parts further. It is clear that this is far from the most reliable solution, and only the rarity of the operation itself of replacing the battery, SIM card or memory card during normal use of the smartphone helps to alleviate the fate of the camera glass.

Back the rear panel of the Lumia 640 installs without any problems. Replacing the memory card and SIM cards is possible only with the battery disconnected. If one of the Micro-SIM-cards gets stuck, then it can be pushed with a fingernail or other handy means through a special hole in the case. Judging by the fact that in almost every new smartphone, recesses and holes for pushing SIM-cards began to appear, their jamming in the connectors is quite common.

There are holes for the camera lens, LED flash, main speaker and connectors on the back of the smartphone. There are repeaters for the keys. On the inside of the lid, there are three rubber dampers and a black sticker instead of the NFC antenna, which this Lumia 640 does not have.

The plastic keys on the right edge of the Lumia 640 control the volume and power of the mobile computer. Strange, but Microsoft engineers did not provide a traditional button for camera control in Lumia 640. The shape of the keys is flat, the size is sufficient for comfortable control of the smartphone blindly. Extra comfort is provided by long key travel and a distinct click when pressed.

The left side of the Lumia 640 is left blank. There is a headphone hole on the top of the smartphone. At the bottom is a lone Micro-USB-compatible connector for the sync and charge cable.

So the Lumia 640's looks and build are mixed. With the general tradition of design and execution, in the current hero of the review there are many small and one major flaw in terms of the exterior. Let's be honest: the smartphone is inconvenient to use, it is very slippery. Lumia 640 should be immediately hidden in a case or replaced with a back cover, for example, a cover with a front curtain and a card holder.

Screen

The screen parameters of the Lumia 640 are as follows: IPS matrix, resolution 1280 × 720 pixels (HD), 5 ″ diagonal, dot density - 293 dpi. The picture on the screen of the review hero is clear and colorful, individual pixels are invisible.

The display of the smartphone is protected from damage by Corning Gorilla Glass 3. The brightness of the backlight is adjusted manually and automatically.

The capacitive sensor of the Lumia 640 confidently detects up to four simultaneous signals. If there are five or more signals, he begins to confuse them, the signals begin to disappear, and the behavior of the sensor becomes inadequate.

A detailed examination using measuring instruments was carried out by the editor of the "Monitors" and "Projectors and TV" sections Alexey Kudryavtsev.

The front surface of the screen is made in the form of a glass plate with a mirror-smooth surface, resistant to scratches. Judging by the reflection of objects, the anti-glare properties of the screen are not worse than those of the Google Nexus 7 (2013) (hereinafter simply Nexus 7). For clarity, here is a photo in which a white surface is reflected in the turned off screens (on the left - Nexus 7, on the right - Microsoft Lumia 640, then they can be distinguished by their size):

The screen of the Microsoft Lumia 640 is slightly darker (brightness in the photos is 97 versus 111 for the Nexus 7). The tripling of reflected objects in the Microsoft Lumia 640 screen is very weak, which indicates that there is no air gap between the outer glass (aka touch sensor) and the matrix surface (OGS type screen - One Glass Solution). Due to the smaller number of boundaries (such as glass / air) with very different refractive indices, such screens look better in strong ambient light, but their repair in case of cracked outer glass is much more expensive, since the entire screen has to be changed. On the outer surface of the screen there is a special oleophobic (grease-repellent) coating (very effective, better than that of the Nexus 7), so fingerprints are much easier to remove, and appear at a slower rate than in the case of ordinary glass.

When the white field was displayed in full screen and with manual brightness control, its maximum value was 385 cd / m², the minimum was 3.4 cd / m². The maximum value is quite high, and given the excellent anti-glare properties, the image on the screen should be clearly visible in bright daylight. In complete darkness, the brightness can be lowered to a comfortable level. With brightness control, everything is quite complicated. Firstly, on a separate page, the user can select one of three profiles with fixed brightness levels and turn on the mode with automatic brightness adjustment according to the ambient light level (the sensor is located to the right of the front camera eye).

Secondly, on another separate page (near the end of the list of applications and settings), you can go to the next level page and there, for manual mode, adjust the brightness levels for these three profiles.

And for the automatic mode, the degree of sensitivity is adjusted on this page:

Further, for the automatic mode (in it, when the external illumination conditions change, the screen brightness both increases and decreases) for three conditions, we give the screen brightness values ​​for three positions of the sensitivity slider (at minimum, default and maximum). In complete darkness in automatic mode, the brightness decreases to 3.2, 12 and 25 cd / m², respectively (the first value is too low, the other two provide acceptable reading comfort from the screen in complete darkness); in an office lit with artificial light (about 400 lux), the brightness is set at 80, 250 and 385 cd / m2 (the first two values ​​can be considered suitable), in a brightly lit environment (corresponds to lighting on a clear day outdoors, but without direct sunlight - 20,000 lx or slightly more) - rises to 385 cd / m² in any case (maximum, which is expected). As a result, this function works more or less adequately and allows the user to make adjustments to its work. Note that there is an option in the settings, the inclusion of which supposedly improves readability in bright light. It is not clear what actually changes this setting, since when it is activated, the backlight brightness does not change, and visually nothing changes on the screen either - even in bright outside light, even in the dark. At any brightness level, there is no significant backlight modulation, so there is no screen flickering either.

This smartphone uses an IPS-type matrix. The micrographs show the typical IPS subpixel structure:

For comparison, you can see the gallery of photomicrographs of screens used in mobile technology.

The screen has good viewing angles without significant color shift, even with large gaze deviations from the perpendicular to the screen and without tint inversion. For comparison, here is a photo in which the screens of Nexus 7 and Microsoft Lumia 640 display the same images, while the brightness of the screens was initially set to about 200 cd / m² (along the white field in full screen), and the color balance on the camera was forced to 6500 K . White field perpendicular to the plane of the screens:

Note the good uniformity of brightness and color tone of the white field. And the test picture:

The color rendition is good and the colors are saturated on both screens, the color balance differs insignificantly. Now at an angle of approximately 45 degrees to the plane and to the side of the screen:

It can be seen that the colors did not change much on both screens, but in the Microsoft Lumia 640 the contrast decreased to a large extent due to the strong black highlighting. And white box:

The brightness at an angle on both screens has noticeably decreased (at least 5 times, based on the difference in exposure), but in the case of the Microsoft Lumia 640, the brightness drop is slightly larger (the brightness in the photos is 227 versus 230 for the Nexus 7). When deviated diagonally, the black field brightens strongly and acquires a yellowish tint or remains approximately neutral gray. The photos below demonstrate this (the brightness of the white areas in the direction perpendicular to the plane of the screens is the same for the screens!):

And from a different angle:

When viewed from a perpendicular view, the uniformity of the black field is good:

Contrast (approximately in the center of the screen) is normal - about 750: 1. The response time for the transition black-white-black is 23 ms (13 ms on + 10 ms off). The transition between gray tones of 25% and 75% (based on the numerical value of the color) and back takes 37 ms in total. Constructed from 32 points with equal intervals by the numerical value of the shade of gray, the gamma curve did not reveal a blockage either in highlights or shadows, and the exponent of the approximating power-law function turned out to be 2.14, which is close to the standard value of 2.2, while the real gamma the curve deviates little from the power-law dependence:

The color gamut is close to sRGB:

The spectra show that the matrix filters moderately mix the components together:

As a result, the colors visually have a natural saturation. The balance of shades on the gray scale is good, since the color temperature is not much higher than the standard 6500 K, and the deviation from the spectrum of the absolute black body (ΔE) is less than 10, which is considered an acceptable indicator for a consumer device. At the same time, the color temperature and ΔE vary little from shade to shade - this has a positive effect on the visual assessment of the color balance. (The darkest areas of the gray scale can be ignored, since the color balance there is not very important, and the error in measuring color characteristics at low brightness is large.)

Going to the second (far) page with screen settings and choosing the next level of nesting - page Color profile- the user can select one of the preset profiles or a profile in which the color rendition can be adjusted with the sliders for color temperature, hue and saturation.

The last slider slightly changes the color gamut. Pregnant Bright we get:

Pregnant Natural we get:

Profile cold- increased color temperature. Profile standard described above graphically and measurements. Profile bright- increased color saturation. Let's go to the profile additionally... Note that fine tuning using the calibrator is significantly complicated by the lack of numerical indication of current values ​​and the ability to choose your own image for display in the upper part of the screen or at least just a large area of ​​the white field on this page. The numerical result of the correction is shown in the charts above with the caption Corr. There are some improvements, but not fundamental. You can stop at the default profile standard.

Let's summarize. The screen has a sufficiently high maximum brightness and has excellent anti-glare properties, so the device can be used outdoors without problems even on a sunny summer day. In complete darkness, the brightness can be lowered to a comfortable level. It is also acceptable to use the mode with automatic brightness adjustment, which works adequately. The advantages of the screen include an effective oleophobic coating, no flicker and no air gap in the layers of the screen, as well as sRGB color gamut and good color balance. Significant disadvantages - low stability of black to deviation of the gaze from the perpendicular to the plane of the screen. Overall, however, the screen quality is high.

Sound

The Microsoft Lumia 640 has two speakers and one microphone. The phone speaker, which is located at the top of the front panel of the mobile computer, has a high volume and good sound quality. Even with strong external noise, the voice of the interlocutor will be clearly distinguishable.

The main speaker of the Lumia 640 is located at the bottom of the back of the smartphone. Its volume is also high, but the sound quality is average. At maximum power and with an abundance of low frequencies, it begins to wheeze noticeably.

For the main speaker, there is only one hole in the back cover of the smartphone, and even a small diameter. As a result, the speaker is very easy to muffle if you cover the hole with something. The sound volume becomes almost zero, only vibrations will continue to pass through the smartphone body.

The Lumia 640 did not come with a standard headset, so the quality of the headphone output of the smartphone was tested in conjunction with the Sony MDR-XB30ER wired headphones. Subjectively, the sound quality was excellent. Even at the maximum comfortable volume, there was no distortion. It was not possible to get to the maximum possible sound power level - it became scary for the hearing. Thus, with good headphones, the Lumia 640 is perfectly suited for listening to music in any environment.

The volume of the sound in the smartphone changes both programmatically and using two keys on the left side of the device. To play music in the memory of a mobile computer, a regular Xbox Music audio player and the MixRadio program are installed - a streaming radio service client with the ability paid subscription for unlimited listening to audio compositions.

The headphones connected to the Lumia 640 act as an antenna for the smartphone's built-in FM radio. It doesn't work without headphones. The receiver management software has a standard appearance. She can automatically search for stations, stations you like can be collected in a list or placed on the desktop in the form of tiles. Supports RDS technology and audio output to the main speaker of the smartphone.

Camera

As noted, the Lumia 640 and Lumia 640 XL have different cameras. In the tested mobile computer, models with 8 megapixel and 0.9 megapixel sensors were installed for the main and additional cameras, respectively. The physical size of the main camera sensor is 1/4 inch. The f / number of the optical system of the camera is f / 2.2, the focal length is 28 mm. The camera is equipped with an autofocus system. For shooting in low light conditions, an LED flash can be used. Video recording is carried out with a resolution of 1080p.

The f / number of the optical system of the additional camera is f / 2.4. There is no automatic focusing system. Video recording is carried out with a resolution of 720p.

It's a shame that the Lumia 640 doesn't have a traditional camera button. Perhaps the manufacturer makes it clear that for photo experiments it is better to look at another model of a smartphone.

Shooting is controlled by the Lumia Camera app. There are no serious delays when activating the camera, the start of the application takes just over a second.

In addition to the Lumia Camera app, the Lumia 640 has several other photography-related programs: Lumia Stories, Lumia Moments, Lumia Live Photos, Lumia Selfies, and Lumia Photo Studio.

	The shooting quality of the front camera is consistent with 1 megapixel.
	Good sharpness across the field and across plans. It's nice that the trees practically do not merge.
	Branches and even grass are well worked out. The sharpness in the distant shots is good.
	In low light, the camera does quite well.
	Good sharpness across the field and across plans. Not all 13-megapixel cameras are capable of working out the grass in the same way, even in the foreground.
	The camera copes with macro photography.
	The text has been worked out well.

Perhaps, the camera has no obvious drawbacks, except for the low resolution of the matrix. But she fulfills her 8 megapixels in full. However, we have already seen all this in previous non-top smartphones of the Lumia line: a good module and a fairly clean program. Despite the fact that the module is different here, it inherited the best qualities of its predecessors. And this is not surprising: why try to change what has already been successful. The camera successfully combines good optics, a decent sensor and a reasonable moderate program. And it is difficult to find more precise words than “just a good camera” to describe it. For artistic and documentary photography, it is quite suitable.

Software

The Microsoft Lumia 640 smartphone runs on Microsoft Windows Phone 8.1 Update 2 with the Lumia Denim package. In the future, all devices in this series should receive a firmware update based on the upcoming Windows 10 OS.

Traditionally for Microsoft / Nokia devices, a large number of additional software... The list includes Microsoft applications: Office, OneNote, OneDrive, Skype. Together with the smartphone, the user gets 15 GB of OneDrive cloud storage for storing any data and another 15 GB for backup photos. Also, when buying a smartphone, a free subscription to Office 365 services for a period of one year is provided.

Onsite navigation and mapping services: Here Drive + and Here Maps. For some reason, the Here Transit application was absent in the memory of the review hero, but it can be easily installed from the Microsoft application store.

For those who like to take pictures of themselves, others and the surrounding reality, the developers of the smartphone have provided as many as five different applications.

The Lumia 640 was not spared by domestic specifics: instead of the Cortana assistant, when you click on a special button, Yandex search is called up, in addition to the Facebook client, the VKontakte social network application is present in the smartphone's memory, reading lovers can use the client of the virtual bookstore Liters: Read!

Telephone part and communications

All variants of Lumia 640 smartphones are capable of working on 2G and 3G networks. The following frequencies for GSM networks are supported: 850, 900, 1800, 1900 MHz. For WCDMA networks: 850, 900, 1900, 2100 MHz. The maximum data download speed in the 3G network is 42.2 Mbps.

Smartphones supporting LTE networks additionally work with the WCDMA 1700 MHz band. LTE support includes the following frequency bands: LTE FDD B1, B2, B3, B4, B5, B7, B8, B12, B17, B28, TD-LTE B38, B40. In LTE Cat 4 networks, the maximum download speed is 150 Mbps.

Smartphones with two SIM card slots operate according to the Dual Standby scheme: in standby mode both communication channels are active, in the phone call mode the second channel is disabled, the smartphone is “out of range”. Only one SIM-card can work in fast 3G / 4G networks, the second channel is always connected to the 2G network. You can switch between the two channels for data, messages and phone calls without turning off the power of your smartphone.

Testing a sample of the Lumia 640 that has been tested has shown reliable operation of the cellular module. The 3G network was defined both in Moscow and in the Moscow region. The data transfer rate in the WCDMA network turned out to be significantly lower than the declared maximum theoretical, but for the busy cellular networks of the capital region this is normal.

The Bluetooth 4.0 module in the Lumia 640 has a large number of work profiles. In conjunction with the Sony MW1 wireless stereo headset, two of them were tested: A2DP and HSP. The support turned out to be at the highest level: playing music with broadcasting track titles, answering phone calls with transferring not only the phone number, but also the name of the interlocutor from the contact list of the mobile computer.

In conditions home network Wi-Fi with a TP-Link TL-WR1043ND router as an access point, the smartphone demonstrated a data exchange rate of 40 Mbps.

The LTE Lumia 640 models also have an NFC module. A smartphone with support only for 3G networks, which had been in the editorial office, was deprived of it.

But all variants of the Lumia 640 interact in the same way with satellite navigation systems. The smartphone receiver receives a signal from GPS, Glonass and BeiDou satellites. A-GPS technology helps locate satellite signals and determine the approximate location of your smartphone based on data from cellular base stations and Wi-Fi networks.

Performance

The basis for the entire family of smartphones Lumia 640 served as the well-known platform Qualcomm Snapdragon 400 used in countless devices. There is no exact data on which chip modification is installed here - most likely, it is MSM8926. The platform includes four ARM Cortex-A7 processing cores with a maximum operating frequency of 1.2 GHz and an Adreno 305 GPU. The chip is manufactured using the 28 nm manufacturing process.

RAM in all versions of the Lumia 640 is installed in 1 GB, flash memory - 8 GB. Of which 3.3 GB are occupied operating system and pre-installed applications. Additional space for music, photos and videos can be obtained using a microSD memory card, cards with a capacity of up to 128 GB are supported. The Lumia 640 does not support external USB drives.

Introduced almost two years ago, the Qualcomm Snapdragon 400 SoC was originally intended for the mid-range smartphone segment. Since the premiere, its performance and capabilities have been well studied, there is no need to wait for any revelations. Unfortunately, in all respects it is inferior to modern SoCs, even budget level but as the example of the Lumia 640 shows, its capabilities are sufficient for new devices even in 2015. In fact, most of the current line of Nokia / Microsoft Lumia devices use this platform in its various variations.

Let's see what marks the hero of this review received in performance tests.

	Microsoft Lumia 640	Nokia Lumia 735	Nokia Lumia 830	Nokia Lumia 930	Nokia Lumia 1520
	4 × 1.2 GHz Adreno 305 5 ″ 1280 × 720 2500 mAh	4 × 1.2 GHz Adreno 305 4.7 ″ 1280 × 720 2200 mAh	4 × 1.2 GHz Adreno 305 5 ″ 1280 × 720 2200 mAh	4 × 2.2 GHz Adreno 330 5 ″ 1920 × 1080 2420 mAh	4 × 2.2 GHz Adreno 330 6 ″ 1920 × 1080 3400 mAh
AnTuTu (points, more is better)	11719	11917	12001	25036	25473
MultiBench 2 CPU (points, more is better)	16,121	15,838	16,072	31,492	29,749
MultiBench 2 Graphics (points, more is better)	44,674	45,958	46,539	47,636	48,766
PhoneMark (points, more is better)	900	806	816	1946	1774

There is nothing new in the test results, we are facing the same well-known platform.

The GFXBench graphics benchmark results table shows two values ​​for each of the tests. This is due to the fact that in onscreen mode the application generates an image with a resolution of 720p, and in offscreen mode - 1080p.

Let's move on to testing the JavaScript processing speed of the browsers built into smartphones.

* Smartphone tested in Octane 1.0 benchmark

Assortment of cards Micro memory The SD that you can install in your Lumia smartphones is very wide. When buying a MicroSD card, you should pay attention to two things: the actual storage capacity and the class. Not all microSD cards offer the same write speed, and the higher the class, the better results you can achieve. For example, for Class 10, an impressive 10 MB per second is the minimum performance. In this article, we will understand what are the differences between the cards.

The good thing about the microSD card is that it is one of the smallest removable flash memory options. Designed specifically for mobile devices, the card is about the size of a fingernail. You can store your documents, photos, videos, music, games and even some applications on it.

For gamers and photographers: Class 10

If you have, say, Lumia 830, you take a lot of photos, and even use the "raw" DNG format, and do not take your finger off the shutter at all, you need a memory card with the highest write speed so that the device has time to save images.

If you love games with great graphics like Asphalt 8: Airborne or Halo: Spartan Strike, having a high-speed card will ensure your gameplay won't be clouded by lags.

Instagram fans: Class 4 and Class 6

If you are crazy about Instagram, constantly share your #Lumialove online, and even record HD video on your Lumia 730 or Lumia 1520, grade 4 or 6 is fine for you. The higher the better, of course.

Typical use: Class 2

Do you spend most of your memory with documents and music? Second-class cards will be the most attractive solution both in terms of features and price.

If you are not at all ready to spend extra money on expanding memory, but you still need additional space, use cloud storage OneDrive that is already on your Lumia. Up to 30GB is available for free, and when you buy the Lumia 640 and Lumia 640 XL, you also get a one-year Office 365 Personal subscription that includes a terabyte of cloud storage.

The best gadgets of 2019 according to the version of Runet users are named

On January 31, 2020 Hi-Tech Mail.ru summed up the results of the annual award "The best gadget of the year according to Runet". Users have cast over a million votes to select the best products across multiple categories.

Chinese smartphone manufacturers: top 7 best and most reliable brands

Mobile phones from China have long ceased to be considered unreliable and substandard. On average, in their price category, they do not differ in quality from models of brands from any other country. And Chinese phones from Huawei, OPPO and Xiaomi are consistently ranked among the best in terms of speed and value for money.

Stylish and reliable Fly FS526 Power Plus 2 with increased autonomy, smartphone review

The energy-intensive 4000 mAh battery, designed for 15 hours of active use, solves the main problem of modern smartphones - the lack of autonomy of the communication device. Equally important is the fact that, being equipped with a strong technical component, Fly FS526 Power Plus 2 remains budgetary.

BQ Space - one of the best offers in its class, smartphone review

BQ-5201 Space is a solid device - solid materials, perfect build, fairly fresh Mediatek MT6753 hardware platform and good graphics. At the same time, the device weighs only 162 g, that is, it is quite suitable for the beautiful half of humanity.

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Often, the built-in memory alone is not enough. It can be expanded by installing an external flash drive in a special slot on the device. The so-called SD cards store a lot of important and unique information: photos, audio files, videos, applications, notes, and more. And if for some reason the drive fails and Windows Phone does not see the SD card, this can become a serious problem in using the smartphone.

Various technical problems can be the source of this failure. However, the problem can be fixed. There are several effective methods for this.

Reasons for a flash drive read error

The message that SD card not found on Windows Phone may appear quite unexpectedly. Even if before that such problems did not arise and the flash drive worked properly in the device. If this error occurs, first of all, you need to make sure that the memory card used in the device was made by a reliable manufacturer. Otherwise, it is likely that the flash drive is simply out of order and cannot be restored.

Along with this, a reading error can be caused by a number of other reasons that can be corrected:

• - inconsistency of the format of the used card with those supported by devices on the Windows Phone platform;
• - full memory;
• - data protection with a password;
• - software glitch.

For each of the reasons, there is a way to solve it. The most difficult to diagnose is a software failure that will require a complete formatting of the flash drive.

What is Format Matching?

If, when connecting a flash drive, a Windows Phone SD card error, it is worth checking how it meets the requirements.

The flash drive must be in Micro SD format. This information is indicated on the packaging and on the product itself. In addition, its volume should correspond to what is possible for a particular operating system:

• - for the Windows platform 8.1 and version 10, from 4 to 200 GB is allowed;
• - for software version 8, it is possible to use a flash drive with a volume of 4 to 128 GB.

If, however, the specified parameters correspond, but Windows Phone SD card problem it remains to check whether access to it is closed with a password.

How to find out if there is an active password on the flash card

To understand whether the information on the SD card is protected, you need to connect it to your computer. This can be done using a special card reader, or an adapter.

Next, you need to go to the "My Computer" section and find your flash drive in the list of removable media. If, when you try to open it, the PC asks for confirmation of access rights and the information is not available, you must remove the set password. This can be done only on the device on which access protection was established.

In the case when access is open, and the card meets the required parameters, there are two ways to solve the error in the operation of the flash drive: scanning it with subsequent troubleshooting and formatting.

Scan for SD card problems

This procedure also requires a computer connection. Before doing this, the flash drive must be safely removed from the mobile device. To do this, go to the system settings section. In it, select the section responsible for the memory of the device. In the list, find the item SD card. Long press to bring up the context menu and select the "Delete" option from the list that opens.

For the Windows Background 8 platform, the path to the flash drive is through the settings section, which is responsible for applications. Here you can select the item "Memory control", in which the flash drive will be presented. Using the context menu, you will need to click on the item "Eject card".

After the flash drive is removed, you need to connect it to the computer. If you are automatically prompted for a scan and troubleshoot option, you must select it. Or go to the "My Computer" section and click on the appropriate option in the flash card context menu.

In the case where a lot of data is stored on the card, the procedure for troubleshooting and correcting them can take a long time. After its completion, you need to install the card on mobile device and restart your phone.

Formatting a flash drive

The last resort is to completely wipe the memory card. Before doing this, you need to back up the stored data. Otherwise, they will be lost forever.

Formatting is also carried out using a PC. This item can be selected from the context menu of the SD card. In the window that opens, you need to set the required parameters:

• - for drives with a memory capacity from 4 to 32 GB, you must select file system"FAT32" and cell size 32 Kb;
• - for a flash drive with a memory capacity from 64 to 200 GB - "exFAT" and a size of 128 KB.

The formatting procedure can take a long time. Upon completion, the card must be removed from the PC using secure removal. You only need to restore files from a backup in formats compatible with the device. It is JPEG for images and photos, MP4 for video and MP3 for audio files.