M.2 NVMe SSD Explained - M.2 vs SSD

Hello everyone. In this video we are going to talk about solid state drives or Expresso SSDs with M.2 non-volatile memory. These chips are now relatively new and have been around for a few years, and just like the regular 2.5-inch SSDs we are more familiar with with M.2 SSDs, they also use flash memory to store data and it is very fast. But the difference between a regular 2.5-inch SSD and an M.2 SSD is that the M.2 has a completely different form factor and plugs into a different type of slot. M.2, formerly known as next-generation form factor, is a standard used to mount expansion cards internally.

Now, SSDs have drastically surpassed mechanical hard drives in terms of speed, and that's because SSDs have no moving parts. Because they use flash memory to store data compared to mechanical hard drives that use rotating magnetic disks to store data. But in recent years, SSDs have become faster and can move data faster. To unlock the full potential of SSDs, engineers need new technology to unlock the faster speeds of SSDs, and that's where M.2 and NVM Express come in. Before M.2 and NVM Express, the latest SATA 3.0 interface standard was used for hard drives and SSDs and the standard used for an interface for software to communicate with SATA was the Advanced Host Controller Interface, better known as AHCI.

Now, AHCI was mainly developed for mechanical hard drives. It is not made or optimized for SSDs, and that is mainly because it dates back to 2004. Therefore, it creates a bottleneck for current SSDs. The SATA 3.0 bus with AHCI allows data transfer speed at a theoretical speed of 600 Megabytes per second, which is quite fast. However, M.2 NVM Express SSDs do not use the SATA bus. Instead, they use the PCI Express bus, which is much faster than SATA. So, by using the PCI Express bus with an optimized protocol like NVM Express, SSDs can transfer data at a speed of 3 Gigabytes per second, which is very fast.

So M.2 SSDs with NVM Express are about 5 times faster than SATA and AHCI. Now, this speed will vary depending on the motherboard you are using and what SSD. But anyway, it's still much faster than SATA SSDs. NVMe or Non-Volatile Memory Express is a communication protocol developed specifically for SSDs. Basically, it reduces CPU overhead and speeds up operations, reducing latency and increasing I/O operations per second; In other words, it's fast. NVM Express was developed to take full advantage of the capacity of PCI Express storage devices and perform many input/output operations in parallel, meaning that many calculations are performed simultaneously.

A large task is divided into several smaller tasks that can be processed independently. This is now very similar to how a multi-core CPU works with multi-threading where the CPU cores work independently of each other to perform certain tasks. Another advantage that NVM Express has over AHCI is the so-called "command queue". The command queue is a queue to execute the command delay. So, simply put, when commands are sent to a storage unit, they come in a line or queue, and when each command finishes with the station, it moves on to the next command in the queue. AHCI now allows a queue with up to 32 commands in the queue.

But NVM Express allows 64,000 queues and with each queue 64,000 commands. So if you want to get the most out of NVM Express, you can theoretically run 4 billion 96 million commands. The M.2 SSD connects to the motherboard in the M.2 slot. It simply slides into the spring-loaded slot and secures with a single screw, and that's it. There are no other connections to make. Therefore, there is no connection cable or separate power cable. It's like an expansion card. Now, not all motherboards are going to have an M.2 slot. Because, as I said before, this is a relatively new technology that has only been around for a few years.

So if you want to use an M.2 NVM Express SSD, make sure your motherboard supports it. You need to make sure it has an M.2 slot and supports NVM Express technology. It is also important to note that not all M.2 SSDs feature NVM Express technology or use the PCI Express bus. Because some M.2 use the SATA bus, which is much slower. There is actually no speed advantage between an M.2 SATA SSD and a standard 2.5-inch SSD. So you should be sure before purchasing a new motherboard and SSD, and I also have a link in the description of this video below of an M.2 SSD that I recommend and purchased myself.