Your Guide to Solid State Drives (SSDs)

A solid-state drive is a form of flash memory that replaces legacy mechanical HDDs on computers. SSDs offer fast read and write times and allow computers to boot up quickly. They're compact, reliable and carry similar warranties as good-quality HDDs. Most compact electronic devices, such as tablets, smartphones, gaming consoles and slim laptops, use space-saving SSDs. Additionally, SSDs are increasingly found in desktops and laptops as original equipment and are replacing spinning-disk hard drives in commercial servers and data storage applications.

SSDs have faster read and write speeds than mechanical hard drives. According to Techradar, SATA and mSATA SSDs are usually three times faster than equivalent HDDs, while those using Non-Volatile Memory Express (NVMe) are more than 10 times faster than HDDs.

Major benefits of an SSD include a faster bootup, as the operating system loads almost instantaneously, a more responsive operating system and faster data access. Other benefits are shorter software loading times and rapid read and write operation. This is especially the case when working with data-intensive software, such as editing photos and high-definition videos.

Because computers spend so much time accessing hard drives, the practical consequence of an SSD reader is overall faster speeds that don’t slow down with age or as the drive fills with data.

You can distinguish SSDs in terms of their capacity, read and write technology and form factor.

SSD Capacity

SSD capacity starts at 32 GB and goes up to around 30 TB. SSD drives cost more than comparable-sized HDDs, although the price differential is dropping. For most applications, the suggested minimum capacity of a primary SSD is 256 GB, while a 2 TB SSD is more adequate for most storage applications.

SSD Technologies

SSDs use one of three technologies:

SATA

SATA is well-established and supported by most computers. It's also used for HDDs. The latest SATA III standard, often referred to as Serial ATA-600, supports a raw data transfer rate of 6 Gb per second (Gb/s) and, in practice, allows you to transfer data at 600 MB per second. This is three times faster than the 150 MB/s and 200 MB/s transfer speeds achievable with an older hard drive.

PCI Express

PCI Express refers to a computer bus standard used by devices like graphics cards, Wi-Fi® and USB-C® connectors. PCIe® is faster than SATA, especially newer variants such as PCIe 3×4, which uses four parallel channels and has an effective data rate of nearly 8 Gb/second. Note that NVMe® is the term for the communication protocol used by PCIe, so for practical purposes, they mean the same thing.

SAS

SAS technology, or serial attached SCSI, is primarily used in data centres. It's an old interface that is still very much in use, and commercial SSD manufacturers such as HPE make SAS-compatible SSD drives.

SSD drives have several form factors, including:

• 5-inch SATA: A direct replacement for a 2.5-inch HDD
• mSATA: A compact version of the full-size SATA SSD drive
• M.2: A compact rectangular form factor commonly used as original equipment in laptops that supports faster read and write speeds
• U.2: A high-end version with similar dimensions to a 2.5-inch drive that uses an SFF connector cable
• PCIe SSD Card: An SSD that plugs into the PCI Express slots on desktop computers

SATA SSDs

A SATA SSD uses the standard 2.5-inch hard drive standard commonly found in laptops and, to an extent, in desktop computers. The drives are 70 mm wide, 100 mm long and have a standard 15-pin SATA connection strip. Standard heights are 9.5 mm and 12.5 mm. You can replace any 2.5-inch HDD with a 2.5-inch SSD, although check height compatibility, as you may need an SSD mounting bracket or adapter.

mSATA SSD

The mSATA internal SSD drive is shaped like a business card that’s 50.7 mm long, 29.85 mm wide and 4.85 mm high. The card has a 52-pin mini-SATA connector that’s similar, but not compatible, with the 52-pin PCI Express mini connector. mSATA drives use standard SATA protocols and offer similar performance to SATA SSDs.

M.2 SSD

M.2 SSDs evolved from the mSATA specification. They use the 52-pin PCI Express mini connector. M.2 cards come in different widths and lengths, the most common being the M.2 2280 card that's 22 mm wide and 80 mm long, with a maximum storage capacity of 4 TB. M.2 SSDs have a slot for a securing screw. Many current laptops use M.2 SSDs. The technology is compatible with SATA and PCIe technology.

U.2 SSD

Developed for commercial and enterprise applications, the U.2 SSD has a larger housing and a unique pin configuration. Although intended for use in data centres, U.2 connectors have become relatively common on desktop and server motherboards. U.2 SSDs support SATA and PCIe technologies. 

PCI Express SSD

The PCIe SSD plugs directly into the PCI bus on desktop motherboards, and you can use a PCIe SSD on any computer with a pluggable PCI bus.

With such a variety of SSDs available, there are many ways to add an SSD or replace your HDD. The simplest solution is to replace your 2.5-inch HDD with an SSD. Alternatively, if your computer has ports such as an M.2 or mSATA port, you can use these to add an SSD.

If you have a desktop computer, there are several other options. These include attaching M.2 drives to your motherboard, using a U.2 port or fitting an SSD adapter. You can also plug a PCIe SSD enclosure into PCIe Express slots.

Consumer

Consumer applications include the use of SSDs in laptops, desktops and as external storage. They cost little more than equivalent HDDs, so it's a relatively easy decision when you need to replace or upgrade a drive, especially in terms of performance improvements. You'll find numerous consumer-oriented drives on our website from leading suppliers including Micron and Seagate.

It's generally easy to identify the right type of drive for your computer. The only exceptions are replaceable SSDs for some Apple® products, as some have Apple-specific SSDs that don't comply with industry standards. Suppliers like Transcend specialize in Apple-compatible SSDs.

Commercial Applications

With demands for increased speed and reliability, many data and storage centres have switched from HDDs to SSDs. Reasons include lower power consumption, speed and reliability. Cisco SSDs are a popular choice for many Cisco server systems. Other industrial server manufacturers offering SSDs include HPE and Dell.