What is M.2?
M.2 is a physical interface specification that refers to the appearance of the interface. Its full name is Next Generation Form Factor (NGFF), and it's a new standard introduced by Intel to replace MSATA. Due to its smaller size and faster speed, most laptops now use hard drives with this interface.
There are three types of M.2 interfaces:
- B key (6 gold fingers notched on the left)
- M key (notch 5 golden fingers on the right)
- B&M key (two notches on the left and right)
The B key is also known as the Socket 2 interface and can be compatible with SATA or PCIE x2 channels. The M key is also known as the Socket 3 interface and can use PCIE x4 channels. When purchasing an SSD enclosure, we often see instructions that support M key or B&M key. This is because the B key interface does not support data transmission speed as fast as the M key, so it's gradually being phased out by the market.
Let's take a look at another commonly used storage interface - SATA.
SATA Interface
SATA stands for Serial ATA, and it is a computer bus that transmits data between the motherboard and a variety of storage devices, such as hard disks and optical disk drives. There are three types of data transmission supported by SATA - SATA 1.0, SATA 2.0, and SATA 3.0. Their bandwidths are 1.5Gbps, 3Gbps, and 6Gbps, respectively. Most SATA hard drive enclosures currently support SATA 3.0, which can transfer data at a maximum speed of 600MBps.
M.2 and SATA interface hard disk enclosures are currently the mainstream solutions for external storage of personal computers.
What is NVMe?
NVMe stands for Non-Volatile Memory Express, which is a transmission protocol that was developed specifically for flash memory products. It is considered the best solution for the transmission protocol of SSD products as it maximizes the performance of SSDs while reducing latency. This is why we often see hard drive enclosures titled M.2 NVMe.
What is a Hard Drive Enclosure?
A hard drive enclosure is a box that houses a hard drive or solid-state hard drive. Its primary role is to protect the hard drive from physical damage. Additionally, it enables the hard drive to be easily detachable by using a simple-to-move connection method.
While some people prefer to buy pre-assembled mobile hard drives due to their convenience and relatively low cost, video content creators or technology enthusiasts who prefer a more efficient way of working may choose to assemble an external hard drive themselves.
The Difference between TB3 and USB4 Enclosures
USB Interface
There are three types of USB interfaces: USB-A, USB-B, and USB-C. While USB-A and USB-C are commonly used interfaces found on many devices, the USB-B interface is mainly used for specific equipment such as scanners and printers.
The USB-C interface has become the most popular due to its reversible plug-in feature, which makes it more convenient to use. The latest iPhone 15 already supports the USB-C(Type-C) interface, indicating that it may become a technological development trend.
Data Transfer Speeds:
USB 2.0: Data transmission bandwidth is 480Mbps
USB 3.0: Data transmission bandwidth is 5Gbps
USB 3.1: Data transmission bandwidth is 10Gbps
USB 3.2: Data transmission bandwidth is 20Gbps
USB 4.0: Data transmission bandwidth is 40Gbps
The theoretical data transmission speed of a USB protocol is equal to the transmission bandwidth divided by 8. For example, USB 3.2 has a theoretical data transmission speed of about 2500Mbps, but the actual test speed is only around 1500-1800Mbps. Similarly, USB4.0 has a theoretical data transmission speed of about 5000Mbps, but the actual test speed is only about 3000Mbps.
Thunderbolt Interface
Both Thunderbolt 3 and Thunderbolt 4 protocols use Type-C interfaces and offer a transmission bandwidth of 40Gbps. However, Thunderbolt 3 reserves 18Gbps bandwidth for DP video signals under any circumstances, thereby reducing its data transmission bandwidth to 22Gbps. In comparison, Thunderbolt 4 offers a data transmission bandwidth of 32Gbps. There are other differences between these protocols, but I won't go into detail here.
The theoretical data transmission speed of Thunderbolt 3 is about 2750Mbps, and it can achieve an actual test speed of almost 2800Mbps. The theoretical data transmission speed of Thunderbolt 4 is approximately 4000Mbps, and it can surpass Thunderbolt 3 in terms of actual data transmission speed. However, Intel has never released a chip specifically for Thunderbolt 4 hard drive enclosures. Although JHL8440 is a Thunderbolt 4 chip, it is primarily used to expand additional interfaces, and it is more expensive.
How to Pick the Best Hard Drive Enclosure?
If you are looking to buy an external hard drive enclosure, there are a few things you should consider.
Do you require an HDD or SSD enclosure?
HDD(Hard Disk Drive) is the traditional form of hard drive enclosure in the PC storage market. It is cheaper and has a large storage space, which can reach 8TB or higher. However, it is not very convenient to carry around.
On the other hand, SSD(Solid-State Drive) is a newer type of hard disk storage that has become a popular solution for most people to store data. It is several times faster than HDD and very portable, but it is also more expensive.
What physical size of you need?
If you are planning to purchase an HDD hard drive enclosure, it's important to determine whether you need a 2.5-inch or a 3.5-inch hard drive enclosure. The 3.5-inch hard drive enclosure is significantly larger and heavier than the 2.5-inch one, but there isn't much difference in terms of transfer speed.
The M.2 NVMe SSD Enclosure is a great option for those searching for a more compact hard drive enclosure. The M.2 NVMe SSD is available in four different sizes: 2230, 2242, 2260, and 2280. Even the longest 2280 M.2 NVMe SSD can easily fit in your pocket when installed in a solid state drive enclosure. This makes it an ideal choice for those who are always on the go, whether for travel or business purposes.
Do you need RAID mode?
If you have multiple HDDs or SSDs and want to merge them into a larger hard drive, you can opt for a hard drive enclosure with RAID functionality. Acasis offers RAID Array specifically designed for 2.5-inch HDDs, 3.5-inch HDDs, and M.2 NVMe SSDs. These hard drive enclosures can utilize your hard drives to their full potential. If you are not familiar with RAID MODE, this article can help you: What is RAID Storage?
Do you need offline cloning functionality?
If we have multiple SSDs and need to transfer data from one to another, we require a hard disk enclosure with a cloning function. Acasis offers an M.2 NVMe Enclosure that enables offline cloning, allowing us to copy data without the need for a computer connection.
SSD Enclosure & Dock
When you want a device that can expand both external storage and laptop interfaces, the Acasis 10-in-1 SSD Enclosure Hub and Acasis 6-in-1 40Gbps M.2 NVMe SSD Case & Dock may be what you need. They provide Ethernet, HDMI, TF, SD, and other interfaces, and even allow you to achieve dual 4K60 screen expansion. Think about it, isn’t this exciting?
Conclusion
When looking for an external hard drive enclosure, it's important to consider your individual needs. Typically, we seek products that offer greater speed, larger storage capacity, enhanced stability, and improved portability. In this regard, the M.2 NVMe SSD Enclosure is worth considering. Purplelec offers a range of Thunderbolt hard drive enclosures, USB hard drive enclosures, and RAID Arrays that are designed to meet most people's external storage needs.