Comparison Dell Inspiron 15 7577 [i75581S0DW-418] vs Dell Inspiron 15 7567 [I755810NDW-60B]

The technology by which the matrix of the laptop is made.

Matrices of the TN+film, IPS and *VA types are most widely used nowadays; less common are screens like OLED, AMOLED, QLED, miniLED, as well as more specific solutions like LTPS or IGZO. Here is a more detailed description of all these options:

— TN-film. The oldest, simplest and most inexpensive technology currently in use. The key advantages of this type of display are low cost and excellent response time. On the other hand, such matrices are not of high image quality: brightness, colour fidelity and viewing angles of TN-film screens are at an average level. These indicators are quite enough for working with documents, web surfing, most games, etc.; however, for more serious tasks that require a high-quality and reliable picture (for example, design or photo / video colour correction), such screens are practically unsuitable. Thus, TN-film matrices are relatively rare nowadays, mainly among low-cost laptops; more advanced devices are equipped with better screens, most often IPS.

— IPS (In-Plane Switching). The most popular type of matrix for laptops in the middle and top price range; however, it is increasingly common in low-cost models, and for trans...formers and 2-in-1 devices (see "Type") it is almost a standard option. Screens of this type are noticeably superior to TN-film in terms of the quality of the “picture”: they provide a bright, reliable and rich image that hardly changes when the viewing angle changes. In addition, this technology allows to achieve extensive colour gamuts in various special standards (see below) and is suitable for creating displays with advanced features such as HDR support or Pantone / CalMAN certification (also see below). Initially, IPS matrices were expensive and had a slow response time; however, nowadays, various modifications of this technology are used, in which these shortcomings are fully or partially compensated. At the same time, different modifications may differ in practical characteristics: for example, some are created based on the maximum reliability of the picture, others differ in affordable cost, etc. So it's ok to clarify the actual characteristics of the IPS screen before buying — especially if you plan to use a laptop for specific applications where image quality is critical.

— *V.A. Various modifications of matrices of the "Vertical Alignment" type: MVA, PVA, Super PVA, ASVA, etc. The differences between these technologies are mainly in the name and the manufacturer. Initially, matrices of this type were developed as a compromise between IPS (high-quality, but expensive and slow) and TN-film (fast, inexpensive, but modest in image quality). As a result, *VA screens turned out to be more affordable than IPS and more advanced than TN-film — they have good colour reproduction, deep blacks and wide viewing angles. At the same time, it is worth noting that the colour balance of the picture on such a display changes somewhat when the viewing angle changes. This makes it difficult to use *VA matrices in professional colour work. In general, this option is designed mainly for those who do not need perfect colour accuracy and at the same time want to see a bright and colorful image.

— OLED. Matrices based on the so-called organic light-emitting diodes. The key feature of such displays is that in them each pixel is a source of light in itself (unlike classic LCD screens, in which the backlight is made separately). This design principle, combined with a number of other solutions, provides excellent brightness, contrast and colour reproduction, rich blacks, the widest possible viewing angles and a small thickness of the screens themselves. On the other hand, laptop OLED matrices for the most part turn out to be quite expensive and “gluttonous” in terms of energy consumption, and they wear out unevenly: the more often and brighter a pixel glows, the faster it loses its working properties (however, this phenomenon becomes noticeable only after several years of intensive use). In addition, for a number of reasons, such screens are considered poorly suited for gaming applications. In light of all this, sensors of this type are rare these days — mostly in individual high-end laptops designed for professional colour work and with appropriate features such as HDR support, wide colour gamut and/or Pantone / CalMAN certification (see below).

— AMOLED. A kind of matrices on organic light-emitting diodes, created by Samsung (however, it is also used by other manufacturers). In terms of its main features, it is similar to other types of OLED matrices (see above): on the one hand, it allows you to achieve excellent image quality, on the other hand, it is expensive and wears out unevenly. At the same time, AMOLED screens have even more advanced colour performance combined with better power optimization. And the low prevalence of this technology is mainly due to the fact that it was originally created for smartphones and only recently began to be used in laptops (since 2020).

— MiniLED. Screen backlight system on a substrate of miniature LEDs with a size of about 100-200 microns (µm). On the same display plane, it was possible to increase the number of LEDs several times, and their array is placed directly behind the matrix itself. The main advantage of miniLED technology can be called a large number of local dimming zones, which in total gives improved brightness, contrast and more saturated colors with deep blacks. MiniLED screens unlock the potential of High Dynamic Range (HDR) technology, suitable for graphic designers and digital content creators.

— QLED. Matrices on "quantum dots" with a redesigned LED backlight system. In particular, it provides the replacement of multilayer colour filters with a special thin-film coating of nanoparticles. Instead of traditional white LEDs, QLED panels use blue ones. As a result, a set of design innovations makes it possible to achieve a higher brightness threshold, colour saturation, improve the quality of colour reproduction in general, while reducing the thickness of the screen and reducing power consumption. The reverse side of the QLED-matrices coin is an expensive cost.

— PLS. A type of matrix developed as an alternative to the IPS described above and, according to some sources, is one of its modifications. Such matrices are also characterized by high colour rendering quality and good brightness; in addition, the advantages of PLS include good suitability for high-resolution screens (due to high pixel density), as well as lower cost than most IPS modifications, and low power consumption. At the same time, the response speed of such screens is not very high.

— LTPS. An advanced type of TFT-matrix, created on the basis of the so-called. low temperature polycrystalline silicon. Such matrices have high colour quality, and are also well suited for screens with high pixel density — in other words, they can be used to create small displays with very high resolution. Another advantage is that part of the control electronics can be built directly into the matrix, reducing the overall thickness of the screen. On the other hand, LTPS matrices are difficult to manufacture and expensive, and therefore are found mainly in premium laptops.

— IGZO. An LCD technology that uses a semiconductor material based on indium, gallium, and zinc oxides (as opposed to more traditional amorphous silicon). This technology provides fast response time, low power consumption and very high colour quality; it also achieves high pixel densities, making it well-suited for ultra-high resolution screens. However, while such displays in laptops are extremely rare. This is explained both by the high cost and by the fact that rather rare metals are used in the production of IGZO matrices, which makes large-scale production difficult.

The maximum brightness that a laptop screen can provide.

The brighter the ambient light, the brighter the laptop screen should be, otherwise the image on it may be difficult to read. And vice versa: in dim ambient light, high brightness is unnecessary — it greatly burdens the eyes (however, in this case, modern laptops provide brightness control). Thus, the higher this indicator, the more versatile the screen is, the wider the range of conditions in which it can be effectively used. The downside of these benefits is an increase in price and energy consumption.

As for specific values, many modern laptops have a brightness of 250 – 300 nt and even lower. This is quite enough for working under artificial lighting of medium intensity, but in bright natural light, visibility may already be a problem. For use in sunny weather (especially outdoors), it is desirable to have a brightness margin of at least 300 – 350 nt. And in the most advanced models, this parameter can be 350 – 400 nt and even more.

The contrast of the screen installed in the laptop.

Contrast is the largest difference in brightness between the lightest white and darkest black that can be achieved on a single screen. It is written as a fraction, for example, 560:1; while the larger the first number, the higher the contrast, the more advanced the screen is and the better the image quality can be achieved on it. This is especially noticeable with large differences in brightness within a single frame: with low contrast, individual details located in the darkest or brightest parts of the picture may be lost, increasing the contrast allows you to eliminate this phenomenon to a certain extent. The flip side of these benefits is an increase in cost.

Separately, we emphasize that in this case only static contrast is indicated — the difference provided within one frame in normal operation, at constant brightness and without the use of special technologies. For advertising purposes, some manufacturers may also provide data on the so-called dynamic contrast — it can be measured in very impressive numbers (seven-digit or more). However, you should focus primarily on static contrast — this is the basic characteristic of any display.

As for specific values, even in the most advanced screens, this indicator does not exceed 2000: 1. But in general, modern laptops have a rather low contrast ratio — it is assumed that for tasks that require more advanced image characteristics, it is more...reasonable to use an external screen (monitor or TV).

The result shown by the laptop processor in the Passmark CPU Mark test.

Passmark CPU Mark is a comprehensive test that is more detailed and reliable than the popular 3DMark06 (see above). It checks not only the gaming capabilities of the CPU, but also its performance in other modes, based on which it displays the overall score; this score can be used to fairly reliably evaluate the processor as a whole (the more points, the higher the performance).

The result shown by the laptop processor in the SuperPI 1M test.

The essence of this test is to calculate the number "pi" to the millionth decimal place. The time spent on this calculation is the final result. Accordingly, the more powerful the processor, the smaller the result will be (this SuperPI 1M is fundamentally different from many other tests).

The result shown by the laptop's graphics card in 3DMark06.

This test primarily determines how well a graphics card handles intensive workloads, in particular, with detailed 3D graphics. The test result is indicated in points; the more points, the higher the performance of the video adapter. Good 3DMark06 scores are especially important for gaming laptops and advanced workstations. However, it is difficult to call them reliable, since measurements are made on video cards with different TDPs and an overall average score is given. Thus, your laptop can have either more or less than the specified result - it all depends on the TDP of the installed video card.

The type of drive that is installed in the laptop.

Classic hard drives (HDD) in modern laptops are quite rare in their pure form. Instead, solid-state SSD modules are becoming more common, including in HDD+SSD and SSHD+SSD combinations. Also note that among such modules, M.2 SSDs are very common, which can also support NVMe and/or belong to the advanced Intel Optane series. Here are the main features of these options in various combinations (as well as other drive options that can be found in modern laptops):

— HDD. Traditional hard disk, not complemented by any other type of storage. HDDs are notable for their low cost per gigabyte of capacity, which allows you to create very capacious and at the same time quite inexpensive media. On the other hand, such storages are considered less perfect than SSDs: in particular, they are rather slow, and they also do not withstand shocks and shocks (the latter is especially true in light of the fact that laptops are originally portable devices). Therefore, this option is quite rare nowadays, mainly among low-cost configurations.

— SSD. Solid-state memory based on flash technology. In general, drives of this type are noticeably more expensive than HDDs of a similar volume, but they have a number of advan...tages over them — first of all, this is a high speed of operation, as well as the ability to endure quite strong shocks and vibrations without any problems. However, we emphasize that in this case we are talking about SSDs of the original format that do not use the M.2 interface, do not belong to the Optane series and are not eMMC or UFS modules (see below for all these features). This is the simplest and most affordable type of flash memory — in particular, it usually uses a SATA interface connection, which does not allow you to realize the full potential of such memory. On the other hand, even “regular” SSD modules still work noticeably faster than HDDs, and they are noticeably cheaper than more advanced solutions.

— SSD M.2. SSD module using M.2 connector. For SSDs in general, see above; and the M.2 connector was specifically designed for advanced yet tiny internal components, including solid state drives. One of the features of such a connection is that it is most often carried out according to the PCI-E standard — this provides a high data transfer rate (up to 8 GB / s, potentially more) and allows you to use all the features of SSD drives. At the same time, there are M.2 modules that work on the older SATA interface — its speed does not exceed 600 MB / s, but such equipment is cheaper than modules with M.2 PCI-E. For details, see "M.2 drive interface" — it is this item that allows you to evaluate the specific capabilities of SSD M.2.

— SSD M.2 Optane. An M.2 SSD (see above) belonging to the Intel Optane series. The main feature of such modules is the use of 3D Xpoint technology — it differs significantly from NAND, on which most conventional SSD modules are built. In particular, 3D Xpoint allows you to access data at the level of individual cells and do without some additional operations, which speeds up work and reduces delays. In addition, such memory is much more durable. Its main drawback is a somewhat high cost. It is also worth noting that the superiority of Optane over more traditional SSD modules is most noticeable at the so-called low queue depth — that is, with a small load on the drive, when a small number of requests are received at the same time. However, most everyday tasks (working with documents, surfing the web, relatively undemanding games) are implemented in this mode, so this moment can be considered an advantage — especially since the superiority of Optane, although it decreases, does not disappear with increasing load.

— SSD M.2 NVMe. NVMe is a data transfer standard designed specifically for solid-state SSD memory. It uses the PCI-E bus and allows you to maximize the potential of such memory, significantly increasing the data exchange speed. This can be either the only drive on board or an addition to an HDD or SSHD. Initially, it was believed that NVMe makes sense to be used mainly on high-performance systems, in particular gaming. However, the development and cheaper technology has led to the fact that such drives are also found in simpler laptops.

— HDD+SSD. The presence in the laptop of two separate drives — HDD and a regular SSD (not M.2, not Optane). The advantages and disadvantages of these types of drives are described in detail above; and their combination in one system allows you to combine the advantages and partially compensate for the shortcomings. SSD in such cases usually has a noticeably smaller volume than HDD, and is used to store data for which high access speed is critical: the operating system, work programs, etc. In turn, it is convenient to store information on a hard disk that takes up a significant volume and at the same time does not require a special access speed; a classic example is multimedia files and documents. In addition, the solid state module can be used as a high-speed cache for a hard drive — similar to the SSHD described below. However, this usually requires special software settings, while the "two separate drives" mode is usually available by default.
It is also worth noting that modern laptops are increasingly using HDD bundles not with conventional SSDs, but with more advanced M.2 modules (including M.2 Optane). However, this option also continues to be used — mainly among relatively inexpensive configurations.

— SSHD. A combination drive that combines a hard disk drive (HDD) and a solid state drive (SSD). It differs from the HDD + SSD bundle described above in two ways. Firstly, both carriers are in the same case and are perceived by the system as a single unit. Secondly, the hard drive is mainly used directly for data storage, and SSD memory usually performs an auxiliary function — it works as a high-speed cache for the HDD. In fact, it looks like this: the data from the hard drive, which the user most often accesses, is copied to the SSD and, at the next access, is loaded from the solid state media, and not from the HDD. This allows you to significantly speed up the work compared to conventional hard drives. However in terms of speed, such “hybrids” are still inferior even to conventional SSDs, not to mention M.2 and Optane solutions — but they are much cheaper.

— HDD+SSD M.2. Combination of a classic hard drive with an M.2 solid-state SSD module. For more information about this combination, see "HDD + SSD": almost everything stated there is also relevant for this case, adjusted for the fact that M.2 SSDs are able to provide higher speeds (see also above — in p. " SSD M.2").

— HDD + Optane M.2. Combining a classic hard drive with an Intel Optane M.2 solid-state SSD module. This combination is generally similar to the “HDD + SSD” combination (see above), adjusted for the advanced capabilities of Optane drives (see also “SSD M.2 Optane” above).

— SSHD+SSD M.2. Combining an SSHD with an M.2 SSD. In general, it is similar to the “HDD + SSD M.2” combination (see above), adjusted for the fact that instead of a regular hard drive, a more advanced and high-speed hybrid drive is used (see also above about it). This further increases the cost, but improves performance.

— eMMC. A type of solid-state drive, originally used as built-in permanent memory for smartphones and tablets, but has recently been installed in laptops. It differs from SSD (see above), on the one hand, by lower cost and good energy efficiency, on the other hand, by lower speed and reliability. Thus, eMMC is now found mainly among transformers and laptop-tablets (see "Type") — for them, low power consumption is more important than maximum performance. Also note that such drives are usually made built-in and do not require replacement.

— HDD + eMMC. Combining a classic hard drive with an eMMC solid state module. The features of each type of drive are described in detail above, and their combination is used mainly in laptop-tablet devices (see "Type"). At the same time, the eMMC drive is installed at the top of the device and is designed to store the operating system and the most important data that needs constant access; and the HDD, located in the lower half, is used as additional storage for large amounts of information (for example, movie collections).

— SSD M.2 + eMMC. The combination of two solid-state modules in one laptop — SSD M.2 and eMMC. See above for details on the features of both types of memory, and their combination is a rather exotic option. It is mainly used to increase the total amount of solid-state memory without a significant increase in cost (remember, eMMC is cheaper than an M.2 SSD of the same volume). In addition, while the eMMC module is usually made built-in, the M.2 SSD is removable by definition, and can be replaced with another drive if necessary.

— UFS. Another type of solid-state memory, originally designed for smartphones and tablets — along with the eMMC described above. It differs from the latter both in high efficiency and increased cost. Thus, such drives are extremely rare among laptops: where eMMC capabilities are not enough, manufacturers usually use full-fledged SSDs.

The number of USB C 3.2 gen2 ports provided in the laptop (previously, such connectors were labeled USB C 3.1 gen2 and USB C 3.1).

USB C is universal connector created relatively recently and designed for use in desktop and laptop computers. It is slightly larger than microUSB, has convenient double-sided design (no matter which side the plug is connected to), and also allows for increased power supply and number of special functions. In addition, the same connector is standardly used in the Thunderbolt v3 interface, and technically can be used for other interfaces; so in some laptops USB C has combined purpose - see “Alternate Mode” for more details. And in some laptops (mostly the most compact ones), USB C can also charge the device’s own battery.

Specifically, the USB C 3.2 gen2 version allows for connection speeds of up to 10 Gbps. As for the number of such ports, it is most often small - usually 1 - 2. This is due to the fact that significantly fewer peripherals for USB C are produced than for full-size USB. However, in some configurations the number of connectors of this type can reach 4.

The number of Thunderbolt connectors, as well as their version ( Thunderbolt v3, Thunderbolt v4, Thunderbolt v5
Thunderbolt is a universal high-speed interface primarily known from Apple laptops, but used by other manufacturers as well. Such a connection actually combines several interfaces — at least PCI-E for peripherals and DisplayPort for outputting video (and audio) to external screens, and others in recent versions. Thanks to this, Thunderbolt can be used both as a peripheral connector and as a video output. Even greater versatility of this interface is provided by the daisy chain function — serial connection of several devices (up to 6) to one port; moreover, it can be both monitors and other peripherals, and in Apple technology, other “apple” computers. Thus, a small number of connectors can be compensated by serial connection.

— Thunderbolt 3. Version introduced in 2015. In this generation, developers abandoned the DisplayPort connector in favor of the more versatile USB-C. Thus, the Thunderbolt v3 connection in laptops is often implemented not as a separate connector, but as a special mode of operation of the regular USB-C port (see "Alternate Mode"). And outputs and devices for USB4 (see above) can be initially made compatible with this interface as well (although this is no...t strictly required). Also optional, but a very common feature is Power Delivery support, which allows you to supply connected devices with power up to 100 watts over the same cable. Data transfer rates can reach up to 40 Gbps, but keep in mind that if the wire length is more than 0.5 m, a special active cable may be required to maintain this speed. However, conventional passive USB-C cables are also suitable for working with Thunderbolt v3 — except that the speed may be noticeably lower than the maximum possible (albeit above 20 Gbps, which runs USB 3.2 gen2).

Thunderbolt v4. The latest (at the end of 2020) version of this interface, presented in the summer of the same year. It also uses a USB-C connector. Formally, the maximum throughput remains the same as its predecessor — 40 Gbps; however, a number of improvements have significantly increased the actual connectivity. Thus, Thunderbolt v4 allows you to broadcast a signal simultaneously to two 4K monitors (at least) and provides a data transfer rate according to the PCI-E standard of at least 32 Gbps (against 16 Gbps in the previous version). In addition, this interface is mutually compatible with USB4 by default, and the daisy chain function is supplemented by the ability to connect hubs with up to 4 Thunderbolt v4 ports. Other features include protection against DMA (direct memory access) attacks.

— Thunderbolt v5. In the fifth edition, Thunderbolt continues to rely on the USB C connector. In the default configuration, it provides bidirectional throughput of up to 80 Gbps, and Bandwidth Boost technology allows for speeds up to 120 Gbps. Thunderbolt v5 supports multiple 8K monitors, three 4K monitors with 144Hz refresh rate, or one external display with the fastest refresh rate of 540Hz. In addition, PCIe Gen 4 support ensures sufficient bandwidth for external graphics cards (up to 64 Gbps), which opens up new possibilities for using AI and machine learning. Through the Thunderbolt v5 interface, charging power of up to 240 W is transmitted using USB Power Delivery 3.1 technology - the most powerful and energy-hungry laptops can be safely charged via the USB port.