HDDs and SSDs are devices that write and read data. Although there are differences in capacity and data transfer speed, many people may think that they are basically the same. However, in reality, there are differences in the interface (connection standard). This content introduces connection standards for HDDs and SSDs in detail. Remember this when purchasing a new HDD or SSD so that you may not have any trouble.
1. What is the HDD / SSD interface (connection standard)?
An interface is a standard for connecting HDDs and SSDs to personal computers and peripheral devices. It is necessary for writing and reading data. Basically, only those that support the connection standard of each HDD and SSD can be connected. If the connection standard is different, you may not be able to connect to your computer or TV.
2. HDD connection standard
Typical HDD connection standards are “SATA” and “IDE”. IDE is an old standard, and the current mainstream is SATA. The transfer speed of SATA (Serial ATA) is increasing as the standard is updated from SATA1 → SATA2 → SATA3. Although each SATA are different standard, since these are upper-compatible and have same connector shape, any of them can be connected. However, there is no compatibility between IDE and SATA.
3. SSD connection standard
Typical SSD connection standards are SATA, mSATA, and M.2. These are not compatible because these are different in size and connector shape. SATA is the same standard as HDDs, so if you are considering replacing an HDD with an SSD, it is essential to select an SSD of SATA standard. However, depending on the standard on your PC side (such as when it is SATA2 or SATA1), the SSD speed may not be fully exhibited. We recommend that you carefully check the standards on your PC side and drive side. Currently, although SSDs are also becoming smaller as products become smaller, it seems that the existing 2.5-inch SATA has higher heat dissipation performance. In addition, there are some other connection standards include those that have a dedicated terminal such as MacBook Air, and those that have an SSD itself soldered to the board such as new MacBook Pro.
4. USB2.0 and USB3.0
Interfaces used to connect external HDDs and SSDs are USB2.0, USB3.0, Thunderbolt, and IEEE1394b, and the most popular ones are USB2.0 and USB3.0. The shapes of these two are not significantly different, however the transfer speed are different. The maximum transfer speed of USB2.0 is 480Mbps, and the new standard USB3.0 is 5Gbps.
If both devices have Type-A, the shape of the connectors are same, and the standard itself is backward compatible, so there is no problem connecting to older models. Although, the transfer speed is decided on the USB standard supported by the connected device. If you connect an external HDD or SSD for USB3.0 to an USB2.0 port, the speed may be limited as lower standard USB2.0. In addition, USB3.0 can perform high-speed communication if all devices and cables are compatible, although sometime high-frequency noise generated from those devices may interfere with products using 2.4 GHz band radio waves such as Wi-Fi and Bluetooth.
Recently, even more advanced USB 3.1 has appeared. USB3.1 has two modes, SUPER SPEED (Gen.1) and SUPER SPEED PLUS (Gen.2). Gen.2 is a new era standard that enables communication at a maximum of 10 Gbps and can also supply a large amount of power. The Type-C terminal is widely used as “USB 3.1 Gen.2”. However, because the shape of a connector is different from the previous one, it can only be used with certain compatible models. Since the standard itself is compatible, it is possible to connect by using a conversion cable.
HDDs and SSDs have different performances and functions depending on a connection standard. When purchasing or adding a new HDD or SSD, including an external HDD, we recommend that you check the compatible connection standards for both your main unit and peripheral devices to be connected in advance.
6. Our recommended products
6-1. Internal SSD with DRAM, M.2, NVMe, 512GB [LMD-MPDB512]
[Internal SSD] An ultra-high-speed internal SSD with DRAM that supports M.2 of the high-speed data transfer standard NVMe.
6-2. Internal SSD with replacement kit, comes with HDD case, 480GB [LMD-SS480KU3]
[Replacement kit] This is a replacement kit for replacing an SSD in order to speed up an HDD that is installed as standard on a PC.
6-3. Impact resistant Portable SSD, smooth rubber framed, USB3.1 Gen1, 480GB, Made in Japan [LMD-PBL480U3BK]
[External SSD] USB 3.1 Gen1 compatible, highly durable portable SSD with a thickness of only 15 mm.