SATA uses a 7-pin connector instead of PATA's 40-pin connector. The SATA cable has a smaller area, due to which the air resistance blowing over the computer components is reduced, and the wiring inside the system unit is simplified.
The SATA cable is more resistant to multiple connections due to its shape. The SATA power cord is also designed with multiple connections in mind. The SATA power connector supplies 3 supply voltages: +12 V, +5 V and +3.3 V; however, modern devices can operate without a voltage of +3.3 V, which makes it possible to use a passive adapter from a standard IDE to SATA power connector. A number of SATA devices come with two power connectors: SATA and Molex.
The SATA standard abandoned the traditional PATA connection of two devices per cable; each device relies on a separate cable, which eliminates the problem of the impossibility of simultaneous operation of devices located on the same cable (and the resulting delays), reduces possible problems during assembly (there is no problem of conflict between Slave/Master devices for SATA), eliminates the possibility of errors when using non-terminated PATA cables.
The SATA standard supports the command queuing feature (NCQ since SATA Revision 1.0a [ ]).
Unlike PATA, the SATA standard provides for hot-plugging a device (used operating system) (since SATA Revision 1.0)
SATA connectors
SATA devices use two connectors: 7-pin (data bus connection) and 15-pin (power connection). The SATA standard provides for the ability to use a standard 4-pin Molex connector instead of a 15-pin power connector (at the same time, using both types of power connectors at the same time may damage the device).
The SATA interface has two data paths, from the controller to the device and from the device to the controller. LVDS technology is used for signal transmission, the wires of each pair are shielded twisted pairs.
There is also a 13-pin [ ] combined SATA connector used in servers, mobile and portable devices for thin drives. It consists of a combined connector of a 7-pin connector for connecting the data bus and a 6-pin connector for connecting the device's power supply. To connect to these devices in servers, a special adapter can be used.
| Contact # | Connection order | Purpose | |
|---|---|---|---|
| - | Lock | ||
| 1 | 3 | +3.3 V | |
| 2 | 3 | ||
| 3 | 2 | ||
| 4 | 1 | GND | |
| 5 | 2 | ||
| 6 | 2 | ||
| 7 | 2 | +5 V | |
| 8 | 3 | ||
| 9 | 3 | ||
| 10 | 2 | GND | |
| 11 | 3 | Activity indication and/or staggered spin-up | |
| 12 | 1 | GND | |
| 13 | 2 | +12 V | |
| 14 | 3 | ||
| 15 | 3 | ||
 |
|||
| 15-pin Serial ATA power cable. | |||
Slimline SATA
| Contact # | Connection order | Purpose | |
|---|---|---|---|
| - | Leveling notch | ||
| 1 | 3 | Device Presence | |
| 2 | 2 | +5 V | |
| 3 | 2 | ||
| 4 | 2 | Diagnostic Output | |
| 5 | 1 | Earth | |
| 6 | 1 | ||
Starting with the SATA 2.6 revision, a flat (slimline) connector was defined, designed for small devices - optical drives for laptops. Pin #1 of the slimline indicates the presence of the device, allowing hot swapping of the device. The Slimline signal connector is identical to the standard version. Slimline power connector has a reduced width and reduced pin spacing, so SATA and slimline SATA power connectors are completely incompatible with each other. The slimline power connector pins supply only +5V, not providing +12V and +3.3V.
There are cheap adapters available to convert between SATA and slimline SATA standards.
SATA Revision 1.0 (up to 1.5 Gb/s)
The SATA Revision 1.0 specification was introduced on January 7, 2003. Initially, the SATA standard provided for the bus to operate at a frequency of 1.5 GHz, providing throughput approximately 1.2 Gb / (150 MB / s). (The 20% performance loss is due to the use of the 8b/10b encoding system, where for every 8 bits useful information there are 2 service bits). The throughput of SATA/150 is slightly higher than that of the Ultra ATA (UDMA/133) bus. The main advantage of SATA over PATA is the use of a serial bus instead of a parallel one. Despite the fact that the serial method of exchange is fundamentally slower than the parallel one, in this case this is compensated by the possibility of operating at higher frequencies due to the lack of the need to synchronize channels and the greater noise immunity of the cable. This is achieved by using a fundamentally different method of data transmission (see LVDS).
SATA Revision 2.0 (up to 3Gb/s)
SATA Revision 2.0 specification ( SATA II or SATA 2.0, SATA/300) operates at a frequency of 3 GHz, provides a throughput of up to 3 Gb / s gross (300 MB / s net for data, taking into account 8b / 10b encoding). It was first implemented in the nForce 4 chipset controller from NVIDIA. Theoretically, SATA/150 and SATA/300 devices should be compatible (both a SATA/300 controller with a SATA/150 device and a SATA/150 controller with a SATA/300 device) due to support for speed matching (down), however, for some devices and controllers require manual setting of the operating mode (for example, on Seagate hard drives that support SATA / 300, a special jumper is provided to force the SATA / 150 mode to be turned on).
SATA revision 2.5
Released in August 2005, SATA revision 2.5 consolidated the specification into a single document.
SATA revision 2.6
Released in February 2007, SATA revision 2.6 includes a description of the Slimline connector, a compact connector for use in portable devices.
SATA Revision 3.0 (up to 6Gb/s)
SATA Revision 3.0 specification ( SATA III or SATA 3.0) was introduced in July 2008 and provides a bandwidth of up to 6 Gb / s gross (600 MB / s net for data with 8b / 10b encoding). Among the improvements in SATA Revision 3.0, compared to previous version specifications, in addition to more high speed, improved power management can be noted. Compatibility is also preserved, both at the level of SATA connectors and cables, and at the level of exchange protocols.
SATA Revision 3.1
SATA Revision 3.2 - SATA Express
eSATA
Check information. |
eSATA(External SATA) - connection interface external devices, supporting the "hot swap" mode. It was created a little later than SATA (in the middle of 2004).
Key Features
- Connectors are less fragile and are designed for more connections than SATA, but are physically incompatible with regular SATA, connector shielding has been added.
- Requires two wires for connection: data bus and power cable (in combined USB/eSATA ports, eSATAp (English) Russian, the separate power cable for external eSATA devices has been eliminated).
- The cable length has been increased to 2 m (compared to 1 m for SATA), signal levels have been changed to compensate for losses (the transmission level has been increased and the receiver threshold level has been reduced).
- The average practical data transfer rate is higher than USB 2.0 or IEEE 1394.
- Signal SATA and eSATA are compatible, but use different levels signal.
Support
WindowsTo support hot swap mode, you need to enable AHCI mode in the BIOS. In case the boot Windows disk XP is connected to the controller, which is switched from IDE to AHCI, Windows will stop loading - it is possible to activate this mode in the BIOS only until Windows installation. After enabling the mode in the BIOS, you must install the AHCI controller driver from the floppy disk "using the F6 method" at the beginning of the Windows XP installation.
Can be on installed Windows XP without AHCI, install the AHCI driver manually (by selecting an inf file), then reboot into the BIOS and set SATA mode in incl. (« ON»).
In Windows 7 and higher, AHCI mode is selected using a registry setting. To enable it, you need to set the value of the “start” parameter at HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\msahci to 0 instead of 3 or 4. Then reboot into the BIOS and enable AHCI there.
Almost all distributions support eSATA without any configuration. To be supported, the kernel must be configured with AHCI support.
Power eSATA (eSATAp)
Initially, eSATA only transmits data. A separate cable must be used for power. MicroStar has created a new kind of eSATA connector by combining eSATA (for data) with USB (for power). The new kind connector is called Power eSATA. . This connector allows, when using a Power Over eSATA cable, to connect SATA drives without any additional adapters.
The eSATAp connector is compatible with eSATA and USB 2.0. This means that eSATA and USB plugs can be plugged into an eSATAp socket without any modifications.
+12 Volts
Some hard drives not only +5V supply is required, but also +12V. Many laptops do not have this voltage, so they are equipped with the original version of eSATAp. For desktop computers, which have a more powerful power supply system and a voltage of +12 V, there is an updated version of the eSATAp connector with additional contacts. There is no established name for the extended connector yet. Some manufacturers call it eSATApd (i.e. dual power).
mSATA
by fiber
(16.777.216 when using switches)
for copper
Quad rate
<10,000 (по оптоволокну)
A lot when using switched fabric
see also
Literature
- Mueller C. Upgrading and Repairing PCs / Scott Muller. - 17th ed. - M. : Williams, 2007. - S. 595-605. - ISBN 0-7897-3404-4.
Links
Notes
- Hard Disk Drives, Solid-State Drives & External Storage Products (unavailable link)// HGST Solutions
- Serial ATA Revision 2.6 (indefinite) . Serial ATA International Organization.
- This is what the SATA II mode is called on the sticker on Hitachi hard drives
- SATA 3.1 specifications have been published (indefinite) . SATA-IO (July 18, 2011). Date of treatment July 19, 2011. Archived from the original on February 2, 2013.
- Msata Faq (indefinite) . forum.notebookreview.com. Retrieved October 30, 2011.
When buying a hard drive, various ambiguities may arise regarding any parameters. Quite often, users get confused about hard drive interfaces, although there are, in fact, only two main interfaces - IDE and SATA.
In this article, we will try to thoroughly deal with this important parameter, and also consider in detail each of the most popular interfaces. Also, let's not disregard the morally and physically obsolete, for the current 2014, IDE interface, in order to bury it completely.
So, first you need to understand the concept of an interface, specifically in the context of hard drives. Interface- this is a means of interaction, in the case of HDD, consisting of signal lines, an interface controller and a special protocol (set of rules). As you know, we insert one end of the interface cable (be it IDE or SATA) into the connector on the HDD, and the other end into the connector on the motherboard.
Now let's go through each of the most popular interfaces, but let's start with the older one, which has long gone out of mass consumption, but is still present in a number of legacy systems.
IDE interface (ATA)
IDE - Integrated Drive Electronics (electronics that is built into the drive). It is also called PATA.
As mentioned above, this interface is very outdated. It was developed back in 1986. We will not talk much about this interface and its specifications. We state the fact that it has a rather low data transfer rate compared to SATA. IDE is used only in very old systems whose motherboards do not support the SATA interface, or when an IDE drive is available. Figure 1 shows an IDE cable, and the corresponding connector on the motherboard is shown on (Figure 2).
Fig.1
Fig.2
When buying a new hard drive, you need to familiarize yourself with the interfaces that your motherboard supports ( choice of motherboard). The latest motherboards are often released without IDE connectors, but you can still find quite a few models that support both IDE and SATA interfaces. Again, if you have a SATA interface, it's better to get the appropriate drive with this interface than to go back in time and buy an IDE drive (in the case of motherboards that support both standards).
Interfaces SATA, SATA 2(II), SATA 3(III)
In 2002, the first hard drives appeared, with a progressive, at that time, interface SATA. The maximum data transfer rate of which was 150 MB / s.
If we talk about the benefits, then the first thing that catches your eye is the replacement 80-wire loop(Fig. 1), to a seven-wire SATA cable (Fig. 3), which is much more resistant to interference, which made it possible to increase the standard cable length from 46 cm to 1 m. Also, the corresponding SATA connectors were developed (Fig. 4), which are several times more compact than the connectors of the previous IDE standard. This made it possible to place more connectors on the motherboard, now on new motherboards you can find more than 6 SATA connectors, against the traditional 2-3 IDE, in older motherboards focused on this standard.
Fig.3
Fig.4
Further, the SATA II standard appeared, the data transfer rate reached 300 MB / s. This standard has many advantages, among them: Native Command Queuing technology (it was it that made it possible to achieve a speed of 300 MB / s), hot plugging of disks, executing several commands in one transaction, and others.
Well, in 2009, the interface was introduced SATA 3. This standard provides for data transfer at a speed 600 MB/s(for hard drives, "oh" how redundant).
As an asset of interface improvements, you can add more efficient power management and, of course, an increase in speed.
It should be noted that SATA, SATA II and SATA III, are completely compatible, which is very practical, due to the many upgrades of various components of the system. Also, I would like to draw attention to the fact that the SATA interface is used by SSD drives and DVD / CD drives. It is for fast SSD drives that the high speeds of the SATA interface will be very useful.
In the form of a small summary of this article, I will say again that with choosing a hard drive(specifically interface), you need to pay attention to which of the standards your motherboard supports. In light of current trends, this will most likely be one of the SATA standards. And for old motherboards and hard drives, the IDE standard always remains.
Now, doubts about which interface to choose: IDE or SATA should disappear. Good luck!
P.S. We have considered the most popular interfaces, there are a large number of more specific ones. For example, removable hard drives use the standard eSATA etc.
The SATA interface (Serial ATA) has almost been forgotten, but the continuity of generations forces from time to time to raise the issue of SATA 2 and SATA 3 compatibility. Today, this mainly concerns the use of new SSD solid-state drives, as well as the latest models of hard drives connected to motherboard boards released a couple of years ago. As a rule, when it comes to backward compatibility of devices, most users prefer not to notice performance losses, wanting to save money. The same thing happens with sata interfaces: the connector design allows you to connect both SATA 2 and SATA 3, there is no threat to the equipment if the connected device does not match the connector, so “we put what we have - it works”.
There are no structural differences between SATA 2 and SATA 3. By definition, SATA 2 is a data exchange interface with a bandwidth of up to 3 Gb / s, SATA 3 also provides data transfer rates up to 6 Gb / s. Both specifications have a seven-pin connector.
When it comes to hard drives, during normal operation we will not notice a difference between connecting a device via SATA 3 and SATA 2 interfaces. Hard mechanics do not provide high speeds, 200 Mb / s can be considered the limit (at 3 Gb / s maximum bandwidth). The release of hard drives with SATA 3 interface can be considered a tribute to the upgrade. Such drives are connected to the ports of the second revision without loss in data exchange speed.
Solid state drives are a completely different matter. SSD devices are available only with the SATA 3 interface. Although you can connect them to the SATA 2 port without compromising the system, however, high read and write speeds are lost. The indicators fall by about half, so the very use of expensive devices does not justify itself. On the other hand, due to technological features, an SSD will work faster than a hard disk even when connected to a slow interface, losing half the speed.
The SATA 3 interface operates at a higher frequency than the previous specification, so latencies are minimized, and a SATA 3 SSD connected to a SATA 2 port will show higher performance than a SATA 2 hard drive. True, this will be noticeable to the average user only during testing , and not during normal application work.
Not critical, but significant difference between SATA 3 and SATA 2 can be considered improved power management of the device.
Findings site
- The bandwidth of the SATA 3 interface reaches 6 Gb / s.
- The bandwidth of the SATA 2 interface reaches 3 Gb / s.
- For SATA 3 hard drives, it can be considered useless.
- When working with SSD SATA 3 provides high data transfer speeds.
- The SATA 3 interface operates at a higher frequency.
- The SATA 3 interface theoretically provides improved device power management.
The different types of keys are marked on or near the end pins (gold-plated) of an M.2 SSD, and on the M.2 connector.
The figure below shows the M.2 SSD keys on an M.2 SSD and compatible M.2 slots with slots to allow drives to be inserted into the appropriate slots:
Note that M.2 B-key SSDs have a different number of end pins (6) compared to M.2 M-key SSDs (5); this asymmetric layout avoids the error of placing an M.2 SSD with a B key into an M slot, and vice versa.
What do the different keys mean?
M.2 SSDs with key B terminators may support SATA and/or PCIe depending on the device, but are limited to PCIe x2 (1000MB/s) speeds on the PCIe bus.
M.2 SSDs with M key end pins may support SATA and/or PCIe protocol depending on the device and support PCIe x4 (2000MB/s) speed on the PCIe bus if the host system also supports x4 mode.
M.2 SSDs with B+M key end pins may support SATA and/or PCIe depending on the device, but are limited to x2 speed on the PCIe bus.
More
Which M.2 configurations and connectors are not compatible?
SSD M.2 Key B Key M Key
SSD edge connector - B Key SSD edge connector - M Key
Incompatible Sockets Not Compatible Sockets - B Key Not Compatible Sockets - M Key
What are the benefits of having a B+M key on an M.2 SSD?
B+M keys on M.2 SSDs provide cross compatibility with various motherboards as well as support for the appropriate SSD protocol (SATA or PCIe). Some motherboard host connectors may be designed to accept only M-keyed SSDs or only B-keyed SSDs. B+M-keyed SSDs are designed to address this issue; however, plugging an M.2 SSD into the socket does not guarantee it will work, it depends on the common protocol between the M.2 SSD and the motherboard.
What types of M.2 SSD host connectors are found on motherboards?
M.2 host connectors can be either B-key or M-key based. They can support both the SATA protocol and the PCIe protocol. Conversely, they can only support one of the two protocols.
If the SSD end pins are B+M keyed, they will physically fit into any host connector, but you should check your motherboard/system manufacturer's specification to ensure protocol compatibility.
How can I find out what length of M.2 SSD my motherboard supports?
You should always check your motherboard/system manufacturer's information to verify supported card lengths, however most motherboards support 2260, 2280, and 22110. Many motherboards have a movable retention screw, allowing the user to install an M.2 2242, 2260, 2280, or even 22100 SSD . The amount of space on the system board limits the size of the M.2 SSDs that can be installed in the socket and used.
What does "socket 1, 2 or 3" mean?
Different connector types are part of the specification and are used to support specific types of devices in a connector.
Socket 1 is for Wi-Fi, Bluetooth®, NFC and WI Gig
Socket 2 is for WWAN, SSD (cache) and GNSS
Socket 3 dedicated to SSD (SATA and PCIe, up to x4 speed)
Does socket 2 support both WWAN and SSD?
If your system has and is not using Socket 2 to support a WWAN card, it can be used for an M.2 SSD (usually a compact form factor like 2242) if it has a B key. An M.2 SATA SSD can be inserted into compatible WWAN connectors if the motherboard supports it. Usually low capacity M.2 2242 SSDs are used for caching along with a 2.5" hard drive. In any case, you should consult the system documentation to verify M.2 support.
Is it possible to hot-plug an M.2 SSD?
No, M.2 SSDs are not meant to be hot plugged. Installing and removing an M.2 SSD is only allowed when the system is powered off.
What are single-sided and double-sided M.2 SSDs?
For some embedded systems with limited space, the M.2 specifications provide for different thicknesses of M.2 SSDs - 3 single-sided versions (S1, S2 and S3) and 5 double-sided versions (D1, D2, D3, D4 and D5). Some platforms may have specific requirements due to space limitations under the M.2 connector, see figure below (Proprietary of LSI).
Kingston SSDM.2 conforms to M.2 double-sided specifications and can be installed in most motherboards that are compatible with double-sided M.2 SSDs; Please contact your sales representative if you require single-sided embedded SSDs.
What is planned for the future?
Next generation M.2 PCIe SSDs will move from using the old AHCI drivers now built into operating systems to a new architecture using the new Non-Volatile Memory Express (NVMe) host interface. NVMe was designed from the start to support NAND-based SSDs (and possibly newer non-volatile memory) and delivers even higher levels of performance. Pre-production testing shows that its speeds are 4 to 6 times faster than today's SATA 3.0 SSDs.
It is expected that it will begin to be implemented in 2015 in the corporate sphere, and then transferred to client systems. As the industry prepares the ecosystem for the release of NVMe SSDs, beta drivers already exist for many operating systems.
Hello! In we examined the hard drive device in detail, but I specifically didn’t say anything about interfaces - that is, ways of interacting a hard drive and other computer devices, or, more specifically, ways of interacting (connecting) a hard drive and a computer.
Why didn't he say? And because this topic is worthy of a volume no less than an entire article. Therefore, today we will analyze in detail the most popular hard disk interfaces at the moment. I’ll make a reservation right away that an article or a post (whichever is more convenient) this time will have an impressive size, but unfortunately there’s no way to go without it, because if you write briefly, it will turn out to be completely incomprehensible.
Computer hard drive interface concept
First, let's define the term "interface". In simple terms (namely, I will express myself with it, if possible, because the blog is designed for ordinary people, such as you and me), interface - the way devices interact with each other and not only devices. For example, many of you have probably heard about the so-called "friendly" interface of a program. What does it mean? This means that the interaction between a person and a program is easier, does not require much effort on the part of the user, compared to the "unfriendly" interface. In our case, the interface is just a way of interacting specifically with the hard drive and the computer motherboard. It is a set of special lines and a special protocol (a set of rules for data transmission). That is, purely physically, it is a cable (cable, wire), on both sides of which there are inputs, and on the hard drive and the motherboard there are special ports (places where the cable is connected). Thus, the concept of an interface includes a connecting cable and ports located on the devices connected by it.
Well, now the most "juice" of today's article, let's go!
Types of interaction between hard drives and the computer motherboard (types of interfaces)
So, the first in line we will have the most "ancient" (80s) of all, in modern HDDs it is no longer found, this is the IDE interface (aka ATA, PATA).
IDE- translated from English "Integrated Drive Electronics", which literally means - "built-in controller". This was later called the IDE as an interface for data transfer, since the controller (located in the device, usually in hard drives and optical drives) and the motherboard had to be connected with something. It (IDE) is also called ATA (Advanced Technology Attachment), it turns out something like "Advanced Technology Attachment". The fact is that ATA - Parallel Data Transfer Interface, for which soon (literally immediately after the release of SATA, which will be discussed below), it was renamed PATA (Parallel ATA).
What can I say, the IDE, although it was very slow (the bandwidth of the data transfer channel ranged from 100 to 133 megabytes per second in different versions of the IDE - and even then purely theoretically, in practice it is much less), but it allowed two devices to be connected to the motherboard at the same time using one loop.
Moreover, in the case of connecting two devices at once, the bandwidth of the line was divided in half. However, this is far from the only drawback of the IDE. The wire itself, as can be seen from the figure, is quite wide and, when connected, will take up the lion's share of the free space in the system unit, which will negatively affect the cooling of the entire system as a whole. All in all IDE is outdated morally and physically, for this reason, the IDE connector is no longer found on many modern motherboards, although until recently they were still installed (in the amount of 1 pc.) On budget boards and on some boards in the middle price segment.
The next, no less popular than the IDE at one time, interface is SATA (Serial ATA), a characteristic feature of which is serial data transmission. It is worth noting that at the time of this writing, it is the most massive for use in a PC.
There are 3 main versions (revisions) of SATA, which differ from each other in bandwidth: rev. 1 (SATA I) - 150 Mb/s, rev. 2 (SATA II) - 300 Mb/s, rev. 3 (SATA III) - 600 Mb/s. But this is only in theory. In practice, the write / read speed of hard drives usually does not exceed 100-150 Mb / s, and the remaining speed is not yet in demand and only affects the speed of interaction between the controller and the HDD cache memory (increases the speed of disk access).
Among the innovations, one can note - backward compatibility of all versions of SATA (a drive with a SATA rev. 2 connector can be connected to a motherboard with a SATA rev. 3 connector, etc.), improved appearance and ease of connecting / disconnecting a cable, increased compared to with IDE cable length (1 meter max, vs. 46 cm on IDE interface), support NCQ functions since the first revision. I hasten to please the owners of old devices that do not support SATA - there are adapters from PATA to SATA, this is a real way out of the situation, allowing you to avoid spending money on buying a new motherboard or a new hard drive.
Also, unlike PATA, the SATA interface provides for "hot-swapping" of hard drives, which means that when the computer's system unit is powered on, you can attach / detach hard drives. True, to implement it, you will need to dig a little into the BIOS settings and enable AHCI mode.
Next in line - eSATA (External SATA)- was created in 2004, the word "external" indicates that it is used to connect external hard drives. Supports " hot swap" drives. The length of the interface cable has been increased compared to SATA - the maximum length is now as much as two meters. eSATA is not physically compatible with SATA, but has the same bandwidth.
But eSATA is far from the only way to connect external devices to your computer. For example firewire- serial high-speed interface for connecting external devices, including HDD.
Supports "hot-swap" hard drives. In terms of throughput, it is comparable to USB 2.0, and with the advent of USB 3.0, it even loses in speed. However, it still has the advantage that FireWire is able to provide isochronous data transfer, which contributes to its use in digital video, as it allows real-time data transfer. Undoubtedly, FireWire is popular, but not as popular as, for example, USB or eSATA. It is rarely used to connect hard drives; in most cases, various multimedia devices are connected using FireWire.
USB (Universal Serial Bus), perhaps the most common interface used to connect external hard drives, flash drives and solid state drives (SSD). As in the previous case, there is support for "hot swapping", a rather large maximum length of the connecting cable - up to 5 meters in case of using USB 2.0, and up to 3 meters - if using USB 3.0. It is probably possible to make a longer cable length, but in this case, the stable operation of the devices will be in question.
The data transfer rate of USB 2.0 is about 40 Mb / s, which is generally low. Yes, of course, for ordinary everyday work with files, a channel bandwidth of 40 Mb / s is enough for the eyes, but as soon as we talk about working with large files, you will inevitably start looking towards something faster. But it turns out there is a way out, and its name is USB 3.0, the bandwidth of which, compared to its predecessor, has increased 10 times and is about 380 Mb / s, that is, almost like SATA II, even a little more.
There are two types of USB cable pins, type "A" and type "B", located at opposite ends of the cable. Type "A" - controller (motherboard), type "B" - connected device.
USB 3.0 (type "A") is compatible with USB 2.0 (type "A"). Types "B" are not compatible with each other, as you can see from the figure.
Thunderbolt(Light Peak). In 2010, Intel demonstrated the first computer with this interface, and a little later, the equally well-known Apple company joined Intel to support Thunderbolt. Thunderbolt is cool enough (well, how else, Apple knows what it's worth investing in), is it worth talking about supporting such features as: the notorious "hot swap", simultaneous connection with several devices at once, really "huge" data transfer speed (20 times faster than USB 2.0).
The maximum cable length is only 3 meters (probably more is not needed). Nevertheless, despite all these advantages, Thunderbolt is not yet "mass" and is used mainly in expensive devices.
Move on. Next in line we have a couple of interfaces that are very similar to each other - these are SAS and SCSI. Their similarity lies in the fact that they are both used primarily in servers that require high performance and the shortest possible access time to the hard disk. However, there is also a reverse side of the coin - all the advantages of these interfaces are offset by the price of devices that support them. Hard drives that support SCSI or SAS are much more expensive.
SCSI(Small Computer System Interface) - a parallel interface for connecting various external devices (not just hard drives).
It was developed and standardized even a little earlier than the first version of SATA. The latest version of SCSI has "hot swap" support.
SAS(Serial Attached SCSI), which replaced SCSI, had to solve a number of shortcomings of the latter. And I must say - he succeeded. The fact is that due to its "parallelism" SCSI used a common bus, so only one of the devices could work with the controller at the same time, SAS does not have this drawback.
In addition, it is backwards compatible with SATA, which is undoubtedly a big plus. Unfortunately, the cost of hard drives with SAS interface is close to the cost of SCSI hard drives, but there is no way to get rid of this, you have to pay for the speed.
If you are not tired yet, I propose to consider another interesting way to connect the HDD - NAS(Network Attached Storage). Network attached storage systems (NAS) are very popular these days. In fact, this is a separate computer, a kind of mini-server responsible for storing data. It connects to another computer via a network cable and is controlled from another computer through a regular browser. All this is necessary in cases where a large disk space is required, which is used by several people at once (in the family, at work). Data from the network storage is transferred to users' computers either via a regular cable (Ethernet) or via Wi-Fi. In my opinion, a very convenient thing.
I think that's all for today. I hope you liked the material, I suggest subscribing to blog updates so as not to miss anything (the form in the upper right corner) and we will meet you in the next blog articles.