Comparison Ugreen 15512 vs Ugreen CM400

The drive interface provided in the pocket's design, in other words, the method of connecting the drive.

Pockets make sense to use for internal drives, so the connection interfaces used are appropriate. It's also worth mentioning that in internal models (see "Type"), the drive interface is often not specified because it matches the interface of the pocket's connection to the computer. As for specific options, the most relevant today are SATA 3 and PCIe 4x. More about them:

— SATA 3. The newest and most advanced, and in drive pockets, also the most widespread version of the SATA interface. This interface is designed for internal drives, primarily hard drives; for SSDs, it is comparatively less suitable because it doesn't allow the full potential of solid-state memory to be realized. Specifically, SATA 3 provides a data transfer rate of up to 600 MB/s, and earlier SATA version drives can also be connected to such ports — albeit with connection speed limited by the slower interface.
It should be noted that in addition to traditional 2.5" and 3.5" SATA drives (see "Form Factor"), connected through the eponymous port, nowadays you can also find SSD modules in M.2 form factor, also using SATA format connection. Such models are noticeably inferior in speed to M.2 PCIe solutions but are also cheaper. They connect to an M.2 slot, which must support SATA.

— SATA 2. The predeces...sor of the above-described SATA 3; this version allows data transfer at speeds up to 300 Mbps. It is found much less frequently in pockets, mainly among outdated models — for example, external solutions using USB 2.0 (see "Connection").

— PCIe. An option found exclusively in models for M.2 drives (see "Drive Form Factor"). Such modules use the M.2 port, where the connection is usually implemented in PCIe format. In this case, the version and number of PCIe lanes are usually specified in the specifications — the supported speeds depend directly on this. For example, the label "PCIe 3.0 2x" means 2 PCIe version 3.0 lanes; this version provides 984 MB/s per lane, so the total speed is approximately 1.97 GB/s. However, nowadays more advanced options are more common — for example, PCIe 3.0 4x, where the speed is around 3.9 GB/s. At the same time, drives and pockets with different versions and numbers of PCIe lanes in this case are usually compatible with each other, except that the speed will be limited by the capabilities of the slower interface.

— SATA/SAS. Models supporting connection via two interfaces — SATA or SAS. The latter is a specialized standard used mainly in server systems; such a feature reflects the intended purpose of pockets with this capability. This versatility is achieved because SAS controllers are compatible with SATA drives, so both types of ports can be provided in the pocket. Meanwhile, SAS significantly exceeds SATA in performance — offering up to 22.5 Gbps, depending on the version (against a maximum of 6 Gbps in SATA). However, it's important to note that the SAS interface does not have a strictly defined type of connector — several types of plugs can be used for such connections; it might be useful to clarify this separately.

Model of the chipset installed “under the hood” of the data storage pocket.

In fact, the chipset is a set of chips that ensures the joint functioning of the drive with the rest of the computer components. In the context of pockets, the chipset is responsible for processing data, transmitting it, monitoring temperature and power consumption to optimize performance, etc.

The method of connecting a pocket with an installed drive to a computer as provided in the design.

Note that this parameter is specified only in cases where the interface for connecting differs from the interface of the drive (see above). This feature is typical for all external models and docks (see "Type"): nowadays they most frequently use USB-A 5Gbps, less often — USB-A 2.0 or USB-C of various versions (see below). In internal solutions, the drive's connector is very rarely different from the pocket's connector, although exceptions occur.

It is also worth mentioning that in external models the connection method is usually determined by the type of complete cable; such a cable is often made detachable, with the possibility to replace it with a "cord" with a different type of plug.

As for specific connection methods, here are their main features:

— USB-A 2.0. USB is used for connecting external peripherals, including pockets; this is the most popular modern interface for such purposes. Version 2.0 is the oldest USB standard still current today. The capabilities of such a connection are rather modest — for instance, the power capacity through the connector is 2.5 W, and the maximum data transfer speed does not exceed 480 Mbps. This is noticeably slower than even SATA 2 (3 Gbps), let alone SATA 3 (6 Gbps); thus this standard is gene...rally considered obsolete, and in pockets with this type of connection, the overall performance is limited to the capabilities of USB-A 2.0. Nevertheless, supporting this interface is inexpensive; for simple tasks that don't involve large amounts of data, it often proves to be quite enough; moreover, USB 2.0 devices are fully compatible with USB ports of newer versions. Thus, today you can still find pockets with this type of connection — mainly the simplest and cheapest models.

— USB-A 5Gbps. This version (previously known as USB 3.2 gen1 and USB 3.0) is the direct successor of USB-A 2.0, providing data transfer speeds 10 times higher — up to 4.8 Gbps — and higher power capacity. The mentioned speed practically matches the capabilities of the popular internal SATA 3 interface; therefore, pockets with this type of connection are extremely widespread today.

— USB-A 10Gbps. Connection to a computer through a full-size USB connector, supporting data transfer speeds up to 10 Gbps. This version is particularly useful for fast SSDs, where a higher-speed interface helps better utilize the drive's capabilities. Compared to USB-A 5Gbps, this variant is more attractive for copying large files, working with video archives, and backups, where not just compatibility but also higher data exchange speed is important. For regular HDDs, the difference may also be present, but the effect is often more modest because the hard drive is usually slower than an SSD.

— USB-C 5Gbps. Modern USB-C connector with data transfer up to 5 Gbps. This option is suitable for regular external SSDs and HDDs, when convenient connection and normal speed for daily tasks are important. Compared to USB-C 10Gbps, it's a more basic option, but for many drives, it is already quite sufficient.

— USB-C 10Gbps. High-speed USB-C interface with data transfer up to 10 Gbps. This option is especially interesting for fast SSDs, where a higher speed cap helps better leverage the drive's capabilities. Compared to USB-C 5Gbps, it is more suited for large video projects, massive archives, frequent copying of heavy files, and using the drive almost like an external working disk. For regular HDDs, the difference is often less noticeable because the hard drive is usually slower than an SSD.

— USB-C 20Gbps. The fastest USB-C option in this line, designed for data transfer up to 20 Gbps. This format is especially interesting for fast SSDs when the pocket is used not just as an external storage, but almost like a full-fledged working disk for large projects, editing, archives, and regular copying of heavy files. It is essential to ensure that a compatible port and cable are available for such speed. Thus, USB-C 20Gbps is an option for those who want to get the most out of an external SSD and not be limited by the interface too soon.

— PCI-E. Connection to a standard PCI-E slot on the motherboard. In other words, such pockets connect to the computer in the same way as video adapters, sound cards, and other expansion cards. This design is used in specific internal models for M.2 SSD form factor drives; such a pocket allows connecting a similar drive to a desktop PC even if the native M.2 ports on the motherboard are occupied, unavailable, incompatible for connection (for example, using the SATA interface while the drive is made for PCI-E), or completely absent.
Note that these pockets are usually compatible with SSD modules on M.2 PCI-E without issues, but compatibility with M.2 SATA should be clarified separately (though such functionality does exist). It should also be noted that PCI-E slots and devices under them can have a different number of lanes, and the general rule here is: the number of lanes of the slot on the motherboard should be at least as many as the card being connected. However, pockets with such connections usually provide no more than 4 lanes, so they can be connected to PCI-E slots starting from 4x.

— IDE. An outdated interface for connecting internal drives. It is extremely rarely encountered in modern pockets — only in certain models designed for installing modern HDDs/SSDs in outdated computers without SATA and other current connectors.

The main material from which the body of the pocket is made.

— Plastic / rubber. This category includes models that use plastic and/or rubber in the construction of cases. The specific ratio and features of the use of these materials are different: the body can be all-plastic, have rubber lining at the ends to increase impact protection, be completely covered with rubber, etc. And in covers (see "Type"), these materials can also be supplemented with others — such as EVA, neoprene or even cloth. Anyway, plastic / rubber cases are found exclusively in external models, including docking stations. Such pockets are somewhat inferior to metal pockets in terms of strength and reliability, but they are cheaper, and in normal everyday use, the mentioned difference is not critical.

— Steel. Cases made of metal are most often made of steel, but there are other options (for example, aluminium alloys). In the inner pockets, only this option is found — this is due to a number of features of such accessories. As for external models in this design, they are much stronger and more reliable than plastic ones, besides, the metal case creates an additional feeling of solidity. The downside of these advantages is the higher price.

The number of separate slots for drives provided in the design of the pocket, in other words, the number of drives for which this model is designed.

In addition to models for one slot, nowadays you can find more capacious solutions — for two drives, or even more. Such "multiplying" is found in three types of devices. The first is large-format pockets for stationary purposes (see above), operating in the format of separate storages for a large amount of data. Such models may support RAID arrays (see above) and other special features. The second type of devices with more than one slot are separate docking stations (see "Type") with similar functionality. The third type is server models (see "Purpose") with an internal installation; they again allow the organization of arrays, but by means of the server itself.

Note that external devices with one slot can be powered from the USB port, but several drives in this case inevitably require a separate PSU (see "Power").

The maximum storage capacity supported by the pocket. In models with multiple disks/SSDs (see "Drive Slots"), this item indicates the largest total volume supported by the device; by dividing this capacity by the number of slots, you can determine the maximum allowable capacity of each individual drive.

The limitation on the maximum volume is relevant mainly for external models, including docking stations (see "Type"). This is due to the fact that fundamentally different interfaces are used for the drive and for connecting the pocket itself in such models (most often SATA and USB, respectively, see above for details). For the normal interaction of such interfaces, an electronic controller is required; and the larger the volume of the installed drive (s) — the higher the requirements for the performance of such a controller.

Note that, other things being equal, supporting large volumes is more expensive, and capacious drives themselves are not cheap. Therefore, when choosing according to this indicator, it is worth considering real needs, and not chasing the maximum numbers.

The type of power provided in the design of the pocket.

This parameter is relevant only for external models (in internal solutions, power is determined solely by the connection interface). The options could be:

— USB. Powered by the same USB port used for the main connection. The advantage of this option is obvious: it allows you to do without unnecessary wires and use the pocket regardless of the presence of sockets (which is important, for example, when working with a laptop on the road). At the same time, the power of USB power is generally low, and besides, it directly depends on the version of the connector (see "Connection"). So for pockets with several disks, this option is not suitable in principle. In other cases, you should pay attention to compatibility when connecting to a USB connector of an older version than is supported by the pocket. For example, a model with USB 3.2 gen1 can be physically connected to a USB 2.0 port without any problems, but it may not have enough power for normal operation. However, more modern versions (USB 3.2 gen1 and gen2) practically do not have such compatibility problems.

- Power Supply. Powered by a separate PSU, usually plugged into a power outlet. These pockets are bulkier and less mobile than USB-powered models, they can't work without power outlets nearby, and the extra wire is a bit of a hassle. On the other hand, the power supply is capable of delivering mor...e power than USB, and this power is constant and does not depend on the version of the port to which the drive is connected. So many stationary models use just such a power supply; and for external pockets for two or more drives, this is generally the only available option.