Buying an SSD isn’t an easy decision. It requires a good amount of knowledge of how computer storage works. This can become even tougher if you are building your computer and picking components on your own. Even for upgrades, SSDs can be tricky to choose. A wrong decision can result in incompatibility.
However, if you know the things to check, it will become very easy for you. There aren’t many things to consider before you go out buying an SSD. You just have to make sure you are choosing the right form factor, interface, capacity, and read/write speed depending on the existing system components.
The SSD must be compatible with the motherboard both physically and on the software level. The PCIe generation must match with the CPU. The port on which the drive is going to connect must have the appropriate PCIe lanes (generally x4) for NVMe drives. For SATA drives, it isn’t that tough because most drives will work on most systems. You just have to match the form factor i.e. choose between M.2 SATA and 2.5″ SATA SSD.
Just don’t get too confused between the technical terms. Understand the form factors, interfaces, NAND Flash types, and important features. When you combine these things with any popular SSD brand, you can easily finalize the right SSD for your system.
In this detailed SSD buying guide, we will only discuss consumer drives and talk a little about enterprise SSDs wherever possible. Also, we will be covering the internal SSDs because choosing external drives isn’t that hard and needs different checks. So, let’s get started.
1. Form-Factor
Form-Factor, in electronics, determines the dimensions, size, and other physical aspects of components. In the case of consumer SSDs, there are three main form factors to choose from: M.2, 2.5″ SATA, and PCIe Add-in Card. In data centers and enterprise environments, you may find SSDs with U.2, E1.S, E1.L, E3 (EDSFF) form factors.
The form factor is the first consideration while choosing your drive. The SSD must fit on an appropriate port before it even starts to interact with the system. You must check the available port on your drive physically for its compatibility with your drive.
1. M.2 Form Factor
The M.2 Form factor is the most popular in modern ultrabooks, laptops, and desktops. It allows the SSDs to become very small and lightweight.
Two main types of SSDs come in the M.2 form factor; M.2 SATA and M.2 NVMe. Both will look similar but work in a completely different way on your system. They will use different interfaces and offer different speeds. We will cover all the aspects in the upcoming section on interfaces. For now, just know that the M.2 form factor is smaller and generally employed to utilize the high storage bandwidth offered by modern systems.
The M.2 NVMe SSDs will always have their connector notch on the right side also called M-Key. The M.2 SATA SSDs will generally have two notches on both sides (B+M Key) or a single notch on the left side called B-Key. You can just look at the port on your system’s motherboard. The ports will also have these notches depending on their physical compatibility.
There are five different sizes on the M.2 Form factors i.e. 2220, 2242, 2262, 2280, 22100. The number “22” here tells the width of the drive while the number “20”, “42”, “60” etc tells the length of the drive.
2280 is the most popular one while 22100 is the least popular form factor in modern systems.
2. SATA 2.5 Inch Form Factor
This form factor is taken from the traditional 2.5″ hard drives. These drives are compatible with any port that supports the 2.5″ hard drives as well. On the laptops, you’ll find dedicated ports for them (if any). On desktops, you have to connect a SATA power cable that comes from the PSU along with a SATA cable that comes from the motherboard.
3. PCIe Add-In Card Form Factor
These drives will look like graphics cards. They will be connected to the PCIe ports. Most drives in this form factor will support NVMe and need at least x4 lanes and even more on the PCIe port. These SSDs are rare but still used in demanding environments.
2. Interface
The interface is how your drive will interact with the system. As we discussed above, there can be two types of drives using the M.2 form factor i.e. M.2 SATA and M.2 NVMe. They may look similar but use different interfaces, hence they use different methods to connect to the system.
1. SATA Interface
This is an old interface that was designed for hard drives. But, it is still applicable with the SATA drives (both M.2 SATA and 2.5-inch SATA). The communication in this interface is directed through the chipset. The AHCI standard is used with the SATA interface to streamline SATA connections with the system. However, this interface isn’t just limited to the SATA ports. The M.2 SATA drives can connect and work with the M.2 NVMe ports. However, the interface will still be SATA combined with AHCI.
SATA-3 is the current and the last release of the SATA interface. It can’t go above the speed of 600MB/s (both read and write). However, this speed is still enough for users who are looking for a drive that is faster than the hard drives but cheaper than the NVMe drives.
2. PCIe Interface
PCIe interface is used by graphics cards, AIC SSDs, NVMe drives, and various other expansion cards. PCIe interface has a huge advantage of higher bandwidth and throughput as compared to any other interface on motherboards. It does it with the help of very fast PCIe lanes. Each port has a dedicated number of PCIe lanes. Each lane will have a two-way connection for sending and receiving data.
3. PCIe Interface with NVMe
The PCIe interface is very fast but still not enough to make the most out of the performance that the NAND Flash memory inside the SSDs can deliver. For that, the NVMe protocol is used. This allows the drives to work on very low latency and make the best use of parallelism.
NVMe works on the OS and SSD levels to optimize the command sets and enable more efficient queue management. This allows the drives to reach speeds like 10 GB/s with the advent of PCIe generation 5.
However, not all ports on the motherboards and not all motherboards support NVMe. Make sure to check for it before making a purchase. Generally, the M.2 port nearest to the CPU on your motherboard will have NVMe support and most PCIe lanes allocated to it. On expensive boards, this support can be given to multiple and even all the M.2 ports.
4. PCIe Generations
PCIe generations are forward and backward-compatible but still, it is important to pick the generations appropriately. It is not worth paying extra money for a PCIe Gen 5.0 if your system can support only up to PCIe 4.0. You won’t be able to get all the speed from your drive in this case. The same goes for the PCIe Gen 4.0 drive on Gen 3.0 motherboards. Also, check the CPU’s PCIe compatibility.
It can be a good decision to buy a drive with a higher PCIe generation for future-proofing.
3. Performance
1. Read/Write Speed
The first thing to check in the performance is the read/write speed of your drive. Generally, NVMe drives with the latest PCIe generations will have to higher performance in the market. For now, the 5th generation NVMe drives are the fastest and offer exceptional read/write speeds. However, there are two types of read/write speeds.
Sequential read/write performance
Imagine you are writing a large video file to your system or moving a folder with thousands of music files. This type of data is called contiguous data. Sequential read/write speed indicates how well the SSD can handle the heavy flow of data which is of a similar kind or big size. A video file of 10 GB size can be considered sequential data.
You will find most drives offering exceptional sequential read/write speed i.e. up to 10 GB/s in 5th generation SSDs. But, this performance doesn’t matter much unless your work includes mostly reading and writing big files that we just discussed. The same concept applies to both reading and writing the data. However, writing will generally be a little slower than reading because of the added overhead that comes with the incoming data.
Most SSD manufacturers will always feature the sequential performance but even this speed will be different in the real world. For SATA drives, this speed can range between 450 MB/s to 550 MB/s in the real world. For NVMe drives, it depends on the generation but the 5th generation drives are literally reaching 10 GB/s sequential speed.
Random read/write performance
Random data performance is what matters the most for day-to-day tasks on our computer. Running software like Google Chrome requires a lot of files to load on the CPU and system memory. These are generally small files like cache files, cookies, history files, and configurations. This data is stored in different parts of the SSD. You can’t call this data contiguous. So, the performance while reading and writing this type of data is called the random performance.
This speed is generally measured in IOPS (Input Output Operations per Second). If your drive has a good random read/write performance, you will get clear benefits in your general computer usage. However, increasing random read/write performance is a real challenge for the manufacturers because of how the SSDs operate. However, the better the random speed, the better will be its performance in tasks like gaming, internet surfing, video editing, and almost everything that you do on your computer.
Most manufacturers will not bother showing the random IOPS performance of their drives. However, you can expect between 50,000 to 100,000 IOPS with the SATA drives and 1 Million to 2 Million IOPS with the NVMe drives on Queue Depth 32 and 16 Threads.
2. IOPS
When we measure or calculate the random read/write performance of our drives, IOPS is used as the parameter instead of MB/s. This helps us get accurate ideas about the random performance. IOPS is a big topic and you can know more about it here. However, keep in mind that random IOPS is the most important parameter to check if you are conscious about your system performance with running software/games and doing other day-to-day tasks. So, the higher it is, the better it is.
4. Storage Capacity
There is not much to do here but I must tell you that choose your OS drive wisely. I would recommend having at least a 500GB drive as your OS drive. SSDs start to slow down as the storage space fills up.
SATA drives are great for raw data storage. So, there is no need to spend much on NVMe drives if the goal is long-term raw storage.
You can also calculate the total required space by adding the size of the operating system, software, files, and games. It is always a good idea to go for some extra space for future-proofing.
A 1TB drive is generally a good option for almost all kinds of systems even if you want to store some data on your system. I keep operating systems in a 500GB drive and get another 500GB SATA drive for raw and long-term data storage.
5. Endurance
All SSDs come with their TBW (Total Terabytes Written). The higher this number, the higher your SSD’s endurance. Also, you should check your drive’s warranty period before purchase.
6. NAND Flash Type
SSDs store data in NAND Flash Memory cells. A cell is the basic unit of storage. The cell is a floating gate transistor with the ability to hold the charge even without power. Millions and Billions of these microscopic cells are combined to create large arrays for data storage. The operations are controlled by an SSD controller.
The flash cells just hold the charge but the controller and the system interpret it in the form of bits.
There are four main types of flash cells; SLC, MLC, TLC, and QLC.
The type of NAND Flash cells determines the performance and longevity of your drive. So, choosing them wisely is really important before you buy your SSD. Most modern SSDs come with the 3D NAND which uses the charge trap flash instead of the traditional 2D NAND. These drives generally have better reliability. Samsung calls its SSDs with 3D NAND the V-NAND Flash. But, the main parameter again is the number of bits stored inside a single cell.
In the consumer market, you just get to choose between TLC and QLC SSDs. Let’s talk about all of these below.
1. SLC NAND Flash
SLC (Single Level Cell) SSDs are used only in data centers and enterprise storage environments. They are extremely expensive. The design is simple because each cell is either holding the charge or is empty meaning it either has logic 0 or 1. In consumer SSD markets, finding these drives is rare. So, there is no point in choosing one for your setup or upgrade.
2. MLC NAND Flash
MLC (Multi-Level Cell) is considered the best type of NAND flash in consumer SSD markets. If you are getting a hand on this drive and you can afford it, it is worth buying it. A little more complex than the SLC drive, MLC SSDs are still pretty good in terms of performance and endurance. In these drives, a single cell is able to hold two-bit and four possible voltage levels. This increases the volume but decreases the longevity as compared to the SLC NAND Flash.
3. TLC NAND Flash
TLC (Triple Level Cell) is the most common type of NAND Flash in the consumer SSD markets. These drives are comparatively cheaper than the MLC drives but still able to deliver good performance and endurance. The design gets more complex and the longevity decreases. In these drives, a single cell is capable of holding three bits and 8 possible voltage levels. This increases the volume a lot more but with a compromise of faster aging.
4. QLC NAND Flash
QLC (Quad Level Cell) is the cheapest NAND Flash memory in the market. These drives are the least reliable and are prone to the fastest damage to their cells. Because a single cell is capable of holding 4 bits and can have 16 possible voltage levels, the complexity becomes way higher than all the above flash types. The endurance is very low compared to all of the drives.
TLC drives are considered the best in terms of price-to-performance ratio. Again, if you can pick an MLC over TLC, it will be a good pick for sure.
7. Features and Specifications
Before buying an SSD, you should check if your drive has TRIM, Encryption, ECC, garbage collection, SMART, secure erase, wear leveling, and power protection. Some SSDs also come with game modes and other advanced features which are good but can contribute to the drive’s price.
Along with that, you should check if the manufacturer has management software for your drive. If you are using a rare operating system, check if your drive is supported with it.
DRAM is another very important thing to check. DRAM-Less SSDs can be cheaper but come with some disadvantages in terms of performance and reliability.
Checking the SSD controller is also very important but needs some extra technical knowledge. Also, there aren’t many controllers to choose from. So, if you are going for the right brand, performance, and interface, the controller will be good as well.
8. Power Consumption and Thermal Management
Power consumption doesn’t matter much in desktops but it can impact your laptop’s battery life. For thermal management, some drives come with heatsinks but may not get installed on laptops. Some drives, especially the faster ones may consume a significant amount of power during heavy read/write operations. So, if the power consumption matters to you, it is worth checking them before you buy.
SSDs get hot during heavy workloads but inside a desktop case where it gets adequate airflow, the heat can be managed. Without any thermal management, SSDs throttle their speed when the temperature goes above around 80°C.
Power consumption and heat are co-related in electronics. If your SSD is reaching very high read/write speeds, it will get hot because the power consumption is higher which eventually results in heat.
9. Price and Value
SATA SSDs generally offer a better price-to-GB ratio. So, if you want more storage at a cheap price, SATA SSDs are the most suitable for you.
The price-to-performance ratio is better with the NVMe drives. These drives are best when it comes to getting the best data read/write speeds. You will also find cheaper NVMe drives, generally without DRAM, encryption, and some other crucial features. QLC SSDs are cheaper as well.