M.2 (NGFF)- the general name of the form factor or physical interface for SSD drives, mobile WiFi adapters, 3G / 4G modems and other computer components for miniature devices like tablets, ultrabooks or nettops.
We have already talked about the new form factor using an example - this material can be found at the link.
However, M.2 was designed not only for SSDs, but also for WiFi, WiGig, Bluetooth adapters, GPS/GLONASS modules (GNSS), NFC modules, and other devices and sensors.
Earlier in mobile devices the listed modules and adapters were connected using the mini connector PCI Express and featured the popular full- or half-length Mini Card form factor. In turn, compact SSD drives had the same Mini Card form factor, but for the mSATA interface.
M.2 or Next Generation Form Factor replaced mSATA and mini PCIe, combined and expanded connectivity, as it is able to work with a large number of logical interfaces (Host Interface). In addition, the M.2 connector takes up less space in a mobile device, and there are several times more options compared to the Mini Card due to the appearance of several M.2 (NGFF) sizes, depending on the width and height.
What you need to know about M.2?
- The M.2 specification (NGFF) includes devices soldered to motherboard, as well as , to which you can connect various devices. The M.2 connector takes up 20% less space than a mini PCIe connector. The M.2 connector has a total of 67 pins, which can be separated by partitions - keys. Depending on the type of key, it is supposed to separate the connected devices according to their purpose.
- The logical interfaces for the M.2 connector can be PCI Express, SATA, USB, Display Port, I2C, SDIO, UART, and others.
- M.2 device sizes are standardized and grouped into types. The width of M.2 devices can be 12, 16, 22 or 30 millimeters. Length - 16, 26, 30, 38, 42, 60, 80 or 110 millimeters. For example, an M.2 SSD that is 22mm wide and 80mm long is labeled "Type2280". (clearly shown in the schematic representation of M.2 devices by standard size).
- The thickness of M.2 devices, more specifically the protruding components at the top and bottom, is also standardized. Devices can be either single-sided or double-sided - elements can be located on one side printed circuit board or two.
M.2 Nomenclature Designation (NGFF) for Devices
Type XX XX- XX-X-X* Type XX XX-XX- X-X*M.2 key name (Key ID) | Number of used contacts of the M.2 connector, pcs. | M.2 connector logical interface options |
A | 8-15 | PCIe x2 / USB / I2C / DP x4 |
B | 12-19 | PCIe x2 / SATA / USB / PMC / IUM / SSIC / UART-I2C |
C | 16-23 | |
D | 20-27 | Key reserved for future uses |
E | 24-31 | PCIe x2 / USB / I2C-ME / SDIO / UART / PCM |
F | 28-35 | Future Memory Interface (FMI)|
G | 39-46 | Will not be used for standard M.2 devices. Reserved for third party devices. |
H | 43-50 | Key reserved for future uses |
J | 47-54 | Key reserved for future uses |
K | 51-58 | Key reserved for future uses |
L | 55-62 | Key reserved for future uses |
M | 59-66 | PCIe x4 / SATA |
* - If the second letter of the key is specified, then the module is universal, compatible with two types of keys in the M.2 slot.
For example, it can be deciphered as follows: width - 22 mm, length 80 mm, double-sided layout, elements protrude 1.35 mm from above and below, suitable for installation in a slot with B or M keys.
In general, manufacturers do not often specify the M.2 module designation. But, in fact, the designation can be compiled independently according to visual signs, as well as by simple measurements of the device.
Which M.2 (NGFF) devices use the M.2 connector with A, E, B, M keys?
What is Socket 1, Socket 2, Socket 3 in relation to M.2 (NGFF) devices?
Indeed, there is the concept of a socket for M.2 devices. The principle of division is clearly shown in the following table:
Soldered to the motherboard | For installation in an M.2 slot | ||||||
M.2 module size | Height | Contacts are identical to the key | M.2 connector key | M.2 module size | Module height | M.2 connector key on module | |
Socket 1Usually, communication modules ( WiFi adapters, Bluetooth, NFC, etc.) |
1216 | S1 | E | ||||
A, E | 1630 | S1, D1, S3, D3, D4 | A, E, A+E | ||||
2226 | S3 | E | A, E | 2230 | S1, D1, S3, D3, D4 | A, E, A+E | |
3026 | S3 | A | A, E | 3030 | S1, D1, S3, D3, D4 | A, E, A+E | |
Socket 2For compact 3G/4G M.2 modems, but other equipment may be available |
B | 3042 | S1, D1, S3, D3, D4 | B | |||
Socket 2For M.2 SSD and other equipment with B+M Generic Key |
B | 2230 | S2, D2, S3, D3, D5 | B+M | |||
B | 2242 | S2, D2, S3, D3, D5 | B+M | ||||
B | 2260 | S2, D2, S3, D3, D5 | B+M | ||||
B | 2280 | S2, D2, S3, D3, D5 | B+M | ||||
B | 22110 | S2, D2, S3, D3, D5 | B+M | ||||
Socket 3M.2 SSD drives only (at least for now) |
M | 2242 | S2, D2, S3, D3, D5 | M, B+M | |||
M | 2260 | S2, D2, S3, D3, D5 | M, B+M | ||||
M | 2280 | S2...D2, S3, D3, D5 | M, B+M | ||||
M | 22110 | S2...D2, S3, D3, D5 | M, B+M |
From the data in the table, it can be seen that Any SSD with a B+M Generic Key can be installed in an M.2 M Key slot. In its turn It is physically impossible to install an SSD with an M key in slot B, even if the logical interface of the devices is the same.
It is for this reason that motherboard manufacturers for SSD installations make an M.2 connector with an M key and two logical interfaces to choose from - PCIe or SATA. But there are exceptions when the M.2 connector on the board is connected only to the PCIe bus or only to the SATA controller - you need to be more careful with this when choosing the right one.
The M.2 connector was introduced to the world a few years ago as a standard to take full advantage of SSDs, allowing them to be installed in small computers.
Cool drive on any computer
A few years ago, on every desktop you could find HDD HDD, cables, cords and jumpers are items known to everyone who has independently modified or repaired a computer.
Hard drives of the time used an ATA connector and interface, which offered 133 MB/s of bandwidth. A few years later, the SATA interface debuted and changed the world of storage media forever.
SATA has gone through three generations, the latter of which is still in use today. The first, that is, SATA 1, provides throughput at the level of MB / s, SATA 2 allows you to reach 300 MB / s, and SATA 3 - 600 MB / s.
New storage solutions
The beginning of the 21st century is the time of the greatest popularity of HDDs - their prices were low, so that everyone could afford several tens of gigabytes of memory, and a few years later - several terabytes.
At the same time, solid state drives began to be produced, which were used in mobile devices, memory cards, portable USB drives, as well as in computers, like SSD drives(solid-state drive).
The advantage of SSD is incomparably higher speed of writing and reading data, as well as the absence of mechanical elements, which increases resistance to shocks and falls.
SSD drives may be small, but due to the popularity of the SATA interface, they began to be produced in the format of 2.5-inch drives, similar to HDDs.
Backward compatibility has its drawbacks
The SATA interface was created much earlier than SSD drives, so even latest version unable to use all possibilities. First of all, this is due to the limitation of 600 MB / s, that is, the maximum bandwidth of the SATA 3 interface. This is a big problem, because SSD performance can be much more.
They tried to fix the problem of large media sizes by introducing the mSATA standard, which is a connector directly on the computer motherboard. The solution made it possible to install SSDs in netbooks and ultrabooks, saving space and reducing their weight.
Unfortunately, the mSATA standard was based on the SATA 3 interface and is therefore also limited to 600 MB/s.
The M.2 connector is the future of solid state media
M.2 standard debuted as the Next Generation Form Factor, that is, as a "new generation connector". In 2013, officially renamed to M.2.
Development is primarily due to by Intel, which first used it in motherboards with H97 and Z97 chipsets for the latest generation of processors Intel Core(Haswell Refresh).
M.2 is a slot for an expansion card installed directly on the motherboard. Designed with solid state drives, Wi-Fi cards, Bluetooth, NFC and GPS in mind.
Depending on the function, there are several variants of M.2 cards on the market: 2230, 2242, 2260, 2280 and 22110. The first two digits are the width (22 mm in any case), and the remaining numbers are the length (30 mm, 42mm, 80mm or 110mm). In the case of modern SSDs, the 2280 option is most often used.
M.2 standard to contact motherboard uses a PCIe interface (PCIe 3.0 is currently being developed) that allows you to bypass the limitations of the SATA 3 interface. Depending on the number of supported PCI Express lanes, throughput M.2 drives for PCIe 3.0 x1 can reach 1 Gb/s, and for PCIe 3.0 x16 up to 15 Gb/s.
M.2 connector can support PCI Express, PCIe and SATA protocol. If an M.2 PCIe drive is connected to a motherboard that only supports the SATA standard, it will not be visible to the system and will not be usable. The same situation will occur when we connect the M.2 SATA drive to a computer that supports only the PCIe interface.
The M.2 media connector may have different locations. Cards with B, M, B+M keys are available on the market. Buying an SSD, you should first make sure which connectors your motherboard supports in your computer.
Drives with key B will not fit in the slot, with key M and vice versa. The solution to this problem is the B+M key. A motherboard with this socket provides compatibility with both types of drives. However, it should be borne in mind that this is not the only factor indicating compliance.
NVMe technology is the new standard
Old hard drives HDD and SSD to connect the controller with operating system use the AHCI protocol. Just like the SATA interface, it was created back in the days hard drives(HDD) and is not able to use the maximum capabilities of modern SSDs.
That is why the NVMe protocol was created. It is a technology built from the ground up, designed with the fast semiconductor carriers of the future in mind. It is characterized by low latency and allows you to perform more operations per second with less CPU usage.
To use NVMe-enabled media, your motherboard must support UEFI.
Which M.2 drive to choose
When buying an M.2 drive attention should be paid to:
- The size of the M.2 connector that the motherboard has (2230, 2242, 2260, 2280 and 22110)
- The type of dongle that has an M.2 connector on the motherboard (M, B, or B+M)
- Interface support (PCIe or SATA)
- Generation and number of PCIe lanes (e.g. PCIe 3.0x4)
- Support for AHCI or NVMe protocol
Currently the best choice is an M.2 SSD using PCIe 3.0x4 interface and NVMe technology. This solution will provide comfortable work in games and programs that require very fast read / write and advanced graphics processing.
Some solid-state drives are also equipped with a heatsink that lowers the temperature, thereby increasing performance and stability.
- 1 General information
- 2 History
- 3 SI units
- 3.1 Basic units
- 3.2 Derived units
- 4 Non-SI units
- Prefixes
General information
The SI system was adopted by the XI General Conference on Weights and Measures, some subsequent conferences made a number of changes to the SI.
The SI system defines seven major and derivatives units of measure, as well as a set of . Standard abbreviations for units of measurement and rules for writing derived units have been established.
In Russia, there is GOST 8.417-2002, which prescribes the mandatory use of SI. It lists the units of measurement, gives their Russian and international names, and establishes the rules for their use. According to these rules, only international designations are allowed to be used in international documents and on instrument scales. In internal documents and publications, either international or Russian designations can be used (but not both at the same time).
Basic units: kilogram, meter, second, ampere, kelvin, mole and candela. Within the SI, these units are considered to have independent dimensions, i.e., none of the base units can be derived from the others.
Derived units are obtained from the basic ones using algebraic operations such as multiplication and division. Some of the derived units in the SI System have their own names.
Prefixes can be used before unit names; they mean that the unit of measure must be multiplied or divided by a certain integer, a power of 10. For example, the prefix "kilo" means multiplying by 1000 (kilometer = 1000 meters). SI prefixes are also called decimal prefixes.
Story
The SI system is based on the metric system of measures, which was created by French scientists and was first widely introduced after the French Revolution. Before the introduction of the metric system, units of measurement were chosen randomly and independently of each other. Therefore, the conversion from one unit of measure to another was difficult. Moreover, in different places applied different units dimensions, sometimes with the same name. The metric system was to become convenient and unified system measures and weights.
In 1799, two standards were approved - for the unit of length (meter) and for the unit of weight (kilogram).
In 1874, the CGS system was introduced, based on three units of measurement - centimeter, gram and second. Decimal prefixes from micro to mega were also introduced.
In 1889, the 1st General Conference on Weights and Measures adopted a system of measures similar to the GHS, but based on the meter, kilogram and second, since these units were recognized as more convenient for practical use.
Subsequently, basic units were introduced for measuring physical quantities in the field of electricity and optics.
In 1960, the XI General Conference on Weights and Measures adopted the standard, which for the first time was called the "International System of Units (SI)".
In 1971, the IV General Conference on Weights and Measures amended the SI, adding, in particular, the unit for measuring the amount of a substance (mol).
The SI is now accepted as the legal system of units by most countries in the world and is almost always used in the field of science (even in countries that have not adopted the SI).
SI units
After the designations of units of the SI System and their derivatives, a period is not put, in contrast to the usual abbreviations.
Basic units
Value | unit of measurement | Designation | ||
---|---|---|---|---|
Russian name | international name | Russian | international | |
Length | meter | meter (meter) | m | m |
Weight | kilogram | kg | kg | kg |
Time | second | second | With | s |
The strength of the electric current | ampere | ampere | BUT | A |
Thermodynamic temperature | kelvin | kelvin | To | K |
The power of light | candela | candela | cd | cd |
Amount of substance | mole | mole | mole | mol |
Derived units
Derived units can be expressed in terms of base units using mathematical operations multiplication and division. Some of the derived units, for convenience, have been given their own names, such units can also be used in mathematical expressions to form other derived units.
The mathematical expression for a derived unit of measure follows from the physical law by which this unit of measure is determined or the definition of the physical quantity for which it is introduced. For example, speed is the distance a body travels per unit time. Accordingly, the unit of speed is m/s (meter per second).
Often the same unit of measurement can be written in different ways, using a different set of basic and derived units (see, for example, the last column in the table ). However, in practice, established (or simply generally accepted) expressions are used that best reflect the physical meaning of the measured quantity. For example, to write the value of the moment of force, N×m should be used, and m×N or J should not be used.
Value | unit of measurement | Designation | Expression | ||
---|---|---|---|---|---|
Russian name | international name | Russian | international | ||
flat corner | radian | radian | glad | rad | m×m -1 = 1 |
Solid angle | steradian | steradian | Wed | sr | m 2 × m -2 = 1 |
Celsius temperature | degree Celsius | °C | degree Celsius | °C | K |
Frequency | hertz | hertz | Hz | Hz | from -1 |
Strength | newton | newton | H | N | kg×m/s 2 |
Energy | joule | joule | J | J | N × m \u003d kg × m 2 / s 2 |
Power | watt | watt | Tue | W | J / s \u003d kg × m 2 / s 3 |
Pressure | pascal | pascal | Pa | Pa | N / m 2 \u003d kg? M -1? s 2 |
Light flow | lumen | lumen | lm | lm | cd×sr |
illumination | luxury | lux | OK | lx | lm / m 2 \u003d cd × sr × m -2 |
Electric charge | pendant | coulomb | Cl | C | A×s |
Potential difference | volt | voltage | AT | V | J / C \u003d kg × m 2 × s -3 × A -1 |
Resistance | ohm | ohm | Ohm | Ω | B / A \u003d kg × m 2 × s -3 × A -2 |
Capacity | farad | farad | F | F | Kl / V \u003d kg -1 × m -2 × s 4 × A 2 |
magnetic flux | weber | weber | wb | wb | kg × m 2 × s -2 × A -1 |
Magnetic induction | tesla | tesla | Tl | T | Wb / m 2 \u003d kg × s -2 × A -1 |
Inductance | Henry | Henry | gn | H | kg × m 2 × s -2 × A -2 |
electrical conductivity | Siemens | siemens | Cm | S | Ohm -1 \u003d kg -1 × m -2 × s 3 A 2 |
Radioactivity | becquerel | becquerel | Bq | bq | from -1 |
Absorbed dose of ionizing radiation | Gray | gray | Gr | Gy | J / kg \u003d m 2 / s 2 |
Effective dose of ionizing radiation | sievert | sievert | Sv | Sv | J / kg \u003d m 2 / s 2 |
Catalyst activity | rolled | catal | cat | kat | mol×s -1 |
Non-SI units
Some non-SI units of measurement are "accepted for use in conjunction with the SI" by the decision of the General Conference on Weights and Measures.
unit of measurement | international name | Designation | SI value | |
---|---|---|---|---|
Russian | international | |||
minute | minutes | min | min | 60 s |
hour | hours | h | h | 60 min = 3600 s |
day | day | day | d | 24 h = 86 400 s |
degree | degree | ° | ° | (P/180) glad |
minute of arc | minutes | ′ | ′ | (1/60)° = (P/10 800) |
arc second | second | ″ | ″ | (1/60)′ = (P/648,000) |
liter | liter (liter) | l | l, L | 1 dm 3 |
ton | tons | t | t | 1000 kg |
neper | neper | Np | Np | |
white | Bel | B | B | |
electron-volt | electronvolt | eV | eV | 10 -19 J |
atomic mass unit | unified atomic mass unit | a. eat. | u | =1.49597870691 -27 kg |
astronomical unit | astronomical unit | a. e. | ua | 10 11 m |
nautical mile | nautical miles | mile | 1852 m (exactly) | |
node | knot | bonds | 1 nautical mile per hour = (1852/3600) m/s | |
ar | are | a | a | 10 2 m 2 |
hectare | hectare | ha | ha | 10 4 m 2 |
bar | bar | bar | bar | 10 5 Pa |
angstrom | angström | Å | Å | 10 -10 m |
barn | barn | b | b | 10 -28 m 2 |
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Books
- Hydraulics. Textbook and workshop for academic bachelor's degree, Kudinov V.A.
- Hydraulics 4th ed., trans. and additional Textbook and workshop for academic baccalaureate, Eduard Mikhailovich Kartashov. The textbook outlines the basic physical and mechanical properties of liquids, issues of hydrostatics and hydrodynamics, gives the basics of the theory of hydrodynamic similarity and mathematical modeling ...