Microsoft Lumia 640 Dual Sim Specifications, Tests and Review

The Microsoft Lumia 640 Dual Sim has dimensions 141.3 mm × 72.2 mm × 8.8 mm. Its weight is 145 g.

The screen size reaches 5" inches. Phones with smaller displays have the advantage of being easier to use with one hand. However, compared to phones with large screens, they provide a lower user experience. Nevertheless, if you don't plan to watch movies or play games on your phone regularly and just expect basic functionality, this size should be good enough for you. The disadvantage of LCD displays is the relatively lower color contrast displayed, as the technology cannot display absolute black well. Also due to the higher power consumption, LCD displays are no longer as common in phones. Even so, some manufacturers still equip their phones with LCD technology. However, modern smartphones are already using OLED technology. The advantage of LCD phones is that they tend to be cheaper to build than OLED technology.

Display Resolution of Microsoft Lumia 640 Dual Sim is 1280 x 720 pixels. A higher display resolution is a prerequisite for a sharper image. The standard for mid-range phones today is a Full HD resolution of 1920 × 1080 px. Cheaper phones, which usually have a smaller diagonal, have an HD resolution of 1280 × 720 px. Smaller resolutions can only be found in older models. Best phones, on the other hand, have a 4K resolution of 3840 x 2160 px. Another important factor having impact on the final image is display´s pixel density. In case of this model, the value reaches 294 ppi. With pixel density, the higher the value, the sharper the image will be. On average today, the image fineness value is around 350-400 ppi. This will guarantee a sufficiently fine and sharp image for normal use. However, the best phones on the market today are equipped with pixel density of 450 ppi or higher.

Microsoft Lumia 640 Dual Sim is supplied with Qualcomm Snapdragon 400. The number of processor cores is 4. It is a number of cores that plays an important role in evaluating the performance of phone as it is responsible for computing operations. Smartphones already commonly have a core count of around 4 to 8. Multi-core processors can perform better and reduce the processing time of a request to a minimum, which is reflected in the responsiveness of the phone, e.g. in the speed of opening applications. Another important parameter is the processor frequency, which indicates how many instructions the phone can process in one second. Similar to refresh rate, the higher the number, the faster the phone responds. Processor frequency of phone Microsoft Lumia 640 Dual Sim is 1.2 GHz. As standard today, you'll find this value between 1.8 GHz and 2.8 GHz.

One of the most important parameters for user´s decision is often internal memory capacity. The larger it is, the more apps, photos, movies and other files your phone can store. This phone has 8 GB storage. This memory capacity is ideal for those who have a few basic apps and a few dozen photos on their phone. If you don't expect to use your phone to play games or need to store high-resolution photos, this size should be sufficient. There is almost no probability you're likely to see this low capacity on new smartphones. The standard memory today is around 64 and 128 GB. The best phones have internal memory of 256 GB or more. Nowadays, you can usually find one phone model on the market with several different memory sizes. This allows each user to choose what suits them best.

For this model it is possible to increase the storage size by inserting a memory card.

Size of the RAM memory tells us how powerful the phone is. Microsoft Lumia 640 Dual Sim is equipped with 1 GB. Commonly today you will find phones with 6 to 8 GB of RAM. This means that the phone can easily handle normal operation and more demanding applications or games. Higher RAM of 12 GB can be found in best phones on market and are ideal especially for avid gamers. On the other hand, operating memory below 4 GB is more of an issue with lower-end phones and older models. However, even they will find their fans among less demanding users, who don´t want to spend much on buying new phone.

The rear camera of the Microsoft Lumia 640 Dual Sim has only one lens. Single lens is more typical for older phones or lower-end phones with lower quality cameras. The rear cameras of modern phones nowadays are usually equipped with two, three and sometimes even five rear camera lenses. The resolution of main lens is 8 Megapixel. Nonetheless, resolution alone does not necessarily mean a good photo. Therefore, you should look at other parameters such as lens aperture or pixel size. Another important factor is the aperture, which in this case is F/2.2 and determines how much light passes through the sensor. Best phones have an aperture of up to F/1.5. But the most common lenses today are F/1.8 to F/2.2. In this case, the lower the number after the slash, the higher the photo quality.

Digital zoom in this case offers zooming up to 4x. Of course, the higher the lens value, the more distant object can be zoomed in. Nonetheless, the disadvantage of digital zoom is that the quality and sharpness of photo deteriorates when using it.

Front camera
The front camera of phone Microsoft Lumia 640 Dual Sim has one lens. This number of lenses is standard on most smartphones nowadays. The lens is equipped with 0.9 Megapixel. However, do not forget there are other factors than resolution having impact on the final quality of front camera photos.

The battery size of Microsoft Lumia 640 Dual Sim is 2500 mAh. Nevertheless, battery capacity is not the only factor that affects the phone's battery life. For example - the size of the display, the performance of the processor, the use of data functions and, of course, the intensity of use of phone in general all have a significant impact on battery life. Standard for most smartphones today is a battery capacity of around 4500 to 5000 mAH. Phones with this battery size usually guarantee a phone life of at least 1 day. Older or cheaper smartphone models can then reach battery capacities typically around 2500 mAH and below. With this capacity, you may find that if you use your phone heavily, you may need to recharge your phone during the day.

The standby time for this phone is 840 hours and tells us how long the phone lasts on a single charge when you're not actively using it. The phone Microsoft Lumia 640 Dual Sim will last one charge with constant phone calls 1638 minutes.

Standard 4G connectivity is currently being replaced by 5G, but is still the preserve of the latest phones. Microsoft Lumia 640 Dual Sim supports 3G. 3G connectivity is now only found in the oldest phones. The operating system in the case of this model is Windows Phone OS 8.1 with Lumia Denim update.

Bluetooth 4.0 must not be missing from the basic package. It makes it easy to connect wireless headphones to your phone, connect your phone to your TV, tablet, speaker and more.