Comparison Lenovo ThinkPad X395 [X395 20NL0007US] vs Lenovo ThinkPad T490s [T490s 20NX002YUS]

General device type.

In addition to traditional laptops, nowadays you can find varieties such as netbooks, ultrabooks, 2 in 1 tablet laptops and transformers. Here are their main features:

— A laptop. Laptops of a more or less traditional format that do not belong to any of the specific categories described below. The classic, most popular screen size in these models is 15.6 ". 13.3" and 14" laptops are considered compact, laptops with a 17.3" screen are large-format, and larger displays are found in advanced gaming models. At the same time, devices from this category are also very diverse in terms of characteristics and capabilities: they range from “typewriters” designed for education and home tasks, to high-end gaming solutions, and workstations and multimedia complexes.

— Ultrabook. High-end laptops that combine compactness, light weight and advanced features. The diagonal in ultrabooks ranges from 11 "to 14", the thickness of the case does not exceed 21 mm, while the internal equipment usually includes powerful processors, a large amount of RAM, fast drives like SSD and other similar solutions. In addition, many devices from this category are made in a characteristic stylish design and are also designed for...the role of fashion accessories.

— Transformer 360°. Another type of laptop that can turn into a tablet. However, unlike the laptops-tablets described above, in this case, not a removable keyboard is used, but a special swivel connection of the upper and lower blocks. The design of this connection is such that the top of the device can be rotated 360° and placed face up on the keyboard. Thus, the transformer can be converted from a laptop to a tablet without removing the bottom half; this is the fundamental difference between such models and the “2-in-1” described above. This format of work is generally more convenient — no need to look for a place for the removed keyboard, there is no risk of forgetting or losing it; in addition, the mounting design usually allows you to use the device in the format of a “photo frame” — an inclined tablet on a stand without a keyboard. Thus, transformers have become more widespread today than collapsible laptops-tablets. Their disadvantages include the inability to reduce weight by removing the keyboard. The diagonal of such devices can be from 12" to 17".

— 2 in 1 (laptop-tablet). Laptops that can turn into tablets. In such models, the entire “hardware” (or at least its key components) is placed in the upper half, the screen is made touch-sensitive, and the lower half with the keyboard can be completely separated. From traditional tablets, which can also be equipped with keyboards, such devices differ in three main points. The first is more powerful hardware: in particular, most 2-in-1 models carry full-fledged laptop processors (up to and including Core i7), while tablets mainly use CPUs similar to smartphone chips. The second point is a larger screen size, usually 13 – 15". The third caveat is that the keyboard of a laptop-tablet can include not only a set of keys and a spare battery, but also some system components: a discrete graphics card, an additional drive, etc. .
In general, 2-in-1 models are more versatile than traditional laptops; however, nowadays they are much less common than another similar type of laptop — transformers (see below). This is due to the fact that the removable keyboard is not always convenient: when using a device in tablet format, it usually has to be removed; it is not always possible to find a place nearby for the removed keyboard; besides, it can be forgotten or lost through inattention. However, this design also has advantages: for example, if there is enough tablet on the road, there is no need to carry additional cargo in the form of the lower half of the device.

Diagonal size of laptop display.

The larger the screen, the more convenient the laptop for watching high-definition movies, modern games, working with large-format graphic materials, etc. Large screens are especially important for multimedia and gaming models. On the other hand, the diagonal of the display directly affects the size and cost of the entire device. So if portability is key, it makes sense to pay attention to relatively small solutions; especially since most modern laptops have video outputs like HDMI or DisplayPort and allow connection of large-format external monitors.

In light of all this, the actual maximum for laptops these days is 17"(17.3"); however larger devices (18") reappeared at the beginning of 2023. The standard option for general purpose laptops is 15"(15.6"), less often 16", a diagonal of 13"(13.3") or 14" is considered small by the standards of such And smaller screens can be found mainly in specific compact varieties of laptops — ultrabooks, 2 in 1, transformers, netbooks; among such devices there are solutions for 12 ", 11" and even 10" or less.

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 cd / m2 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 cd / m2. And in the most advanced models, this parameter can be 350 – 400 cd / m2 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 colour gamut of the laptop matrix according to the Rec.709 colour model or according to sRGB.

Colour gamut describes the range of colours that can be displayed on the screen. It is indicated as a percentage, but not relative to the entire variety of visible colours, but relative to the conditional colour space (colour model). This is due to the fact that no modern screen is able to display all the colours visible to humans. However, the larger the colour gamut, the wider the screen's capabilities, the better its colour reproduction.

Specifically, sRGB and Rec.709 are the most popular of today's colour models; they have the same range and differ only in the scope (sRGB is used in computers, Rec. 709 is used in HDTV). Therefore, the closer the colour gamut is to 100%, the more accurately the colours on the screen will match the colours that were originally intended by the creator of the film, game, etc. At the same time, note that such accuracy is not particularly needed in everyday use — it critical only for professional work with colour; and even in such cases, it is more convenient to buy a separate monitor with a wide colour gamut for a laptop, rather than looking for a laptop with a high-quality (and, accordingly, expensive) matrix.

The colour gamut of the laptop matrix according to the Adobe RGB colour model.

Colour gamut describes the range of colours that can be displayed on the screen. It is indicated as a percentage, but not relative to the entire variety of visible colours, but relative to the conditional colour space (colour model). This is due to the fact that no modern screen is able to display all the colours visible to humans. However, the larger the colour gamut, the wider the screen's capabilities, the better its colour reproduction.

The Adobe RGB colour model was originally developed for print applications; the range of colours covered by it corresponds to the capabilities of professional printing equipment. Therefore, theoretically, the extensive coverage of this model will be useful to those involved in the design and layout of high-end printed products. However most laptop screens have very limited Adobe RGB values, rarely exceeding 74%; however, you can also find high-end models where this figure approaches 100%. Of course, the cost of such laptops will also be appropriate; therefore, it makes sense to pay attention to them, first of all, when the ability to work with colour “on the go” is of key importance. If this is to be done in one place, it may be more justified to buy a separate monitor with a wide colour gamut (especially since a monitor with such characteristics is easier to find than a laptop).

Each series combines chips that are similar in general level, purpose, and often also in individual specific features. Moreover, most series include processors of several generations at once, which can differ significantly in actual characteristics. It is worth noting that until recently laptops were equipped almost exclusively with processors from AMD or Intel - until in 2020 Apple introduced its own chip Apple M1 (with updated versions Apple M1 Pro and Apple M1 Max), Apple M2 (2022) with powerful chips M2 Pro, M2 Max and Apple M3, M3 Pro, M3 Max (2023). At the moment, the following series are mainly relevant in laptops:

— AMD Ryzen 3. The most inexpensive series of AMD chips in the Ryzen family (Ryzen 3, Ryzen 5, Ryzen 7 and Ryzen 9) using the Zen microarchitecture. In terms of the general design, Ryzen 3 is similar to its older brothers, but half of the computing cores are deactivated. However, it is quite advanced and is found even in ultrabooks.
...> — Ryzen 5. The second series based on Zen architecture is a more affordable alternative to Ryzen 7 chips. Ryzen 5 chips have somewhat more limited performance characteristics (in particular, a lower clock frequency and, in some models, L3 cache size). Otherwise, they are completely similar to the “sevens” and are also positioned as high-performance chips for gaming and workstations. See "Ryzen 7" below for more details.

- Ryzen 7. The first series of processors from AMD, built on the Zen microarchitecture. It was introduced in March 2017. In general, Ryzen chips (of all series) are promoted as high-end solutions for gamers, developers, graphic designers and video editors. One of the main differences between Zen and previous microarchitectures was the use of simultaneous multithreading, due to which the number of operations per clock was significantly increased at the same clock frequency. In addition, each core received its own floating-point calculation unit, the speed of the first level cache increased, and the L3 cache capacity in Ryzen 7 chips is 16 MB as standard.

— Atom. Processors specifically designed by Intel for mobile devices (including smartphones). They are mainly used in ultra-compact laptops.

— Core M. Processors designed for portable equipment (in particular, ultra-compact laptops) and characterized by extremely low heat generation, allowing the use of passive cooling systems. They were introduced in 2014 as the first serial chips based on the 14 nm process technology.

— Celeron. The most budget series in the modern line of desktop processors from Intel. However, the latest generations come with integrated graphics.

— Pentium. Budget desktop processors from Intel, slightly superior in performance to Celeron, but not up to the Core i3. Also carry integrated graphics.

— Processor. The entry-level processor line that precedes the Core i3 family in the modern Intel hierarchy. Such chipsets are found in entry-level laptops designed for everyday household or office use, as well as undemanding games.

- Core i3. A series of entry-level and mid-level processors, the most budget series in the Core ix family; however, it outperforms the Pentium and Celeron series.

— Core i5. A series of mid-range processors, both in general and in the Core ix family. The architecture is dual- or quad-core, they have a third-level cache, and many models are also equipped with a built-in graphics chip.

— Core i7. A series of productive processors; before the advent of i9 was the most advanced in the "Core i" family. Core i7 chips have at least 4 cores, large level 3 cache and integrated graphics.

— Core i9. Top-level processors released in 2017; the most powerful line of consumer-grade laptop processors at the time of its introduction, displacing Core i7 chips from this position. They have from 6 cores and a volume cache of level 3.

— Apple. A series of processors from Apple, which debuted in November 2020 along with the release of the next generations of MacBook, MacBook Air and MacBook Pro. In the initial configurations, they are equipped with 8 cores - 4 productive and 4 economical; the latter, according to the creators, consume 10 times less energy than the former. This, combined with the 5 nm process technology, has made it possible to achieve very high energy efficiency and at the same time performance. It is also worth noting that the processors of this series are made according to the system-on-chip scheme: a single module combines a CPU, a graphics adapter, RAM (in the first models - 8 or 16 GB), an NVMe solid-state drive and some other components (in particularly Thunderbolt 4 controllers).

The specific model of the processor installed in the laptop, or rather, the processor index within its series (see above). Knowing the full name of the processor (series and model), you can find detailed information on it (up to practical reviews) and clarify its capabilities.

The code name for CPU installed in the laptop.

This parameter characterizes, first of all, the generation to which the processor belongs, and the microarchitecture used in it. At the same time, chips with different code names can belong to the same microarchitecture/generation; in such cases, they differ in other parameters - general positioning, belonging to certain series (see above), the presence / absence of certain specific functions, etc.

Nowadays, the following code names are relevant in Intel processors: Coffee Lake, Comet Lake, Ice Lake, Tiger Lake, Jasper Lake, Alder Lake, Raptor Lake (13th Gen), Alder Lake-N, Raptor Lake (14th Gen), Meteor Lake (Series 1), Raptor Lake (Series 1). For AMD, the list looks like this: Zen 2 Renoir, Zen 2 Lucienne, Zen 3 Cezanne, Zen 3 Barcelo, Zen 3+ Rembrandt, Zen 3+ Rembrandt R, Zen 2 Mendocino, Zen 3 Barcelo R, Zen 4 Dragon Range, Zen 4 Phoenix. Detailed data on different code names can be found in special sources.