The best 10 SSDs in comparison

Are you buying a new PC or upgrading an old one? You might want to consider a computer with a solid-state drive instead of an old-school hard disk drive. Solid-state drives (SSDs) are faster, more durable, and more reliable compared to hard disk drives (HDDs).

There are countless options available on the market, and even if you go for the leading SSD manufacturers, like Samsung, Western Digital, or Crucial, you might get confused between their different product lines.

To help you decide, we have compiled a list with the most important specifications you should take into account when choosing an SSD.

SSD vs. HDD

When it comes to data storage, HDDs and SDDs work differently. HDDs store the data on spinning platters, with a needle-like component called head floating above it. Whenever we need to access data, the head moves to the position of the data. In the case of SSD, there are no moving parts. Data is stored in memory blocks. So there is no question of mechanical failures in SSDs. The most significant advantage of SSD over HDD is performance. If you are looking for a way to make your computer operate fast and efficiently, SSDs are the best bet for you.

But there are a few downsides to SSDs as well. Even though over the years, their price has dropped, they are still quite expensive. You have to spend about $100 to get a 250GB SSD, whereas the same price can get you a 4TB HDD.

Performance and speed

When it comes to measuring the performance of an SSD, there are three key aspects to consider: throughput, latency, and IOPS (Input/Output Operations per Second).

Throughput, the actual data transfer rate, is the second parameter to measure the performance of a storage device. How long it takes to BEGIN a data transfer, called latency, is even more important. IOPS indicates how OFTEN the storage device can perform a data transfer. IOPS and latency are integral performance measuring tools for enterprise and data center.

Another crucial parameter is the Mean Time Between Failures (MTBF), which is the predicted elapsed time between inherent failures of a system during operation. For example, in the case of the Intel 335, the 1.2 million hour MTBF means that if the drive is used at an average of 8 hours a day, a population of 1000 SSDs would be expected to have one failure every 150 days. The MTBF varies from manufacturer to manufacturer but, generally, any device with a value above 1 million is good to go.

Interface and form factors

SATA, mSATA, M.2, and PCIe are the most popular interface options currently available on the market. The form factor depends not only on the type of interface used but also on the physical dimensions of your device.

SATA

At present, the SSD market is dominated by various types of Serial ATA interfaces. With the latest version of SATA, the data exchange rate can go as high as 6Gbps. But not all SSDs are using the latest SATA III interface. The data transfer rates of different versions of SATA interface are presented below:

To get the promised speed, you need to ensure that your computer is SATA III compatible as well. However, even if your computer is not compatible with SATA III, the SSD would still work because all versions of SATA are backward-compatible. However, in such a situation, the data transfer rate is limited.

The form factor of SATA SSDs is pretty much similar to that of HDDs. They usually come with standardized options of 3.5 inches, 2.5 inches, and 1.8 inches. For laptops, the standard form factor is 2.5 inches, and for desktop, it's 3.5 inches, but you can mount a 2.5 inch SSD on a PC using an adaptor. Smaller form factors are suitable for laptops. When buying an SSD for your laptop, also keep an eye for the thickness. The thickness may vary from 5mm to 9.5mm, but some can be as thick as 12mm, and they might not fit.

mSATA

mSATA or mini-SATA interface is identical to SATA in terms of data transfer rate. The smaller form factor of mSATA SSDs makes them ideal for notebooks and laptops. However, the mSATA interface is getting replaced by the M.2 interface.

PCIe

Peripheral Component Interconnect Express or PCIe SSDs use the PCIe slots on the motherboard and are thus capable of high performance. Theoretically, in the PCIe SSDs, transfer rate results can hover anywhere from 1.5GB/s to 3GB/s. The downside is that these SSDs are very expensive. The form factor of PCIe SSDs varies from 4.3 inches to 12.3 inches.

M.2

M.2 is an interface that can use either SATA specification and restrict the bandwidth up to 600MB/s or can use PCIe that provides bandwidth up to 1 Gbps. There is also the possibility to use multiple PCIe lanes (up to 4 PCIe lanes) to get transfer rates of up to 4 Gbps. They have a light and thin chassis and are suitable for portable devices.

Protocols

With different hardware interface specifications like PCIe, we have been able to boost the data transfer rate. But to get full advantage of the hardware, it is crucial to have efficient software protocols specifically optimized for SSDs.

AHCI (Advanced Host Controller Interface) was the protocol used for the storage devices, but it was more optimized for HDDs. NVMe or Non-Volatile Memory Express protocol was developed for low-latency SSDs, paired with an interface like PCIe. Other protocols, such as SATA Express (by Serial ATA International Organization) and SCSI Express, are also used to boost the performance of SSDs using PCIe interfaces.

Security

To secure data, consumer and enterprise SSDs are using hardware-based encryption. On these SSDs, data is always secured with the Advanced Encryption Standard (AES). Nowadays, most SSDs come with 128-bit, 192-bit, or 256-bit AES to secure the data. But your platform should support AES x-bit self-encryption. The advantage of a self-encrypting drive is that it takes place at the BIOS level.

Storage capacity

Typical storage capacities for solid-state drives range between 64GB and 1TB. The number of NAND chips (memory chips) also affects the performance of the SSD. Usually, the higher the storage, the more NAND chips the SSD has. A higher number of memory chips allows the drive to spread out the read and write operations of the data between the chips, effectively increasing performance, a process similar to how RAID works on a computer with multiple hard drives.

The best bet is to use anything beyond 250GB, as it gives you enough space to keep your operating system, games, and other applications. There is also the possibility of using both an SSD and an HDD. Usually, for systems that use both types of data storage, the SSD is used as the boot drive, which has the operating system (because it's faster), and the HDD is used to store files.

In the case of HDDs, when the operating system needs extra space, it overwrites the "not in use" memory zone (the memory available after deleting a file) in one single operation. But a solid-state drive has to first erase all data in this "not in use" space before recording the new data. SSDs are only able to delete data in large 512 kB blocks, which slows down the entire overwriting process. However, new SSDs support TRIM. Whenever you delete a file, the operating system sends a TRIM command to mark the unused data blocks, informing the SSD about which blocks of data are no longer in use. That way, the SSD can write data on the marked space, skipping the cumbersome deletion process.