Storage Drive Glossary

An SSD stores data on flash memory chips rather than spinning disks. The result is near-instant load times, silent operation, and no moving parts to break. SSDs are now the standard choice for laptops and desktops alike.

The traditional spinning disk drive. An HDD stores data on magnetic platters that rotate at high speed. HDDs are slower than SSDs but offer much larger capacities for the price, making them a great fit for backups, media libraries, and bulk storage.

NVMe is the fastest type of SSD available for consumers. It connects directly to the CPU via PCIe lanes rather than going through a slower storage controller. If you want the best performance for gaming, video editing, or heavy workloads, NVMe is the way to go.

An external drive lives outside your computer and connects via a cable, typically USB. They are portable, easy to use, and great for backups, moving files between machines, or expanding storage without opening your case.

PCIe is the high-speed connection that links your SSD directly to the CPU. Each new generation roughly doubles the bandwidth of the previous one. Gen 3 is fast enough for most users, Gen 4 is mainstream for gaming and creative work, and Gen 5 sits at the cutting edge of consumer storage.

Each PCIe generation doubles the data bandwidth available to the drive:

• Gen 3: up to ~3,500 MB/s read. Reliable and affordable.
• Gen 4: up to ~7,000 MB/s read. The sweet spot today.
• Gen 5: up to ~14,000 MB/s read. Cutting-edge, runs hot, and carries a price premium.

Your motherboard and CPU must support the generation you want to take full advantage of it.

SATA is the older interface standard, used by 2.5″ SSDs and traditional HDDs. It tops out around 550 MB/s, which is noticeably slower than NVMe but perfectly fine for everyday computing, secondary storage, or budget builds. SATA SSDs are widely compatible with older systems that predate M.2 slots.

Universal Serial Bus is the plug-and-play connection used by most external drives. USB 3.2 Gen 2 (10 Gbps) is common today and fast enough for most use cases. If you need maximum speed from an external drive, look for USB4 or Thunderbolt instead.

M.2 is the slim, stick-shaped form factor used by modern SSDs. It slots directly into your motherboard with no cables needed. Most M.2 SSDs use PCIe/NVMe for maximum speed, but some use SATA. The most common size is 2280 (22 mm wide, 80 mm long).

The 2.5″ form factor is the standard size for laptop drives and SATA SSDs. It connects via a data cable and sits in a drive bay. Most SATA SSDs use this size, and it fits in any system with a 2.5″ bay or a compatible adapter.

The 3.5″ form factor is the classic desktop hard drive size. It offers the highest capacities available, often 10 TB, 16 TB, or more, at the lowest cost per gigabyte. Common in desktop towers and NAS enclosures.

How fast data can be read from the drive, measured in megabytes per second (MB/s). This is the number most prominently advertised and the one you feel in day-to-day use: booting Windows, opening apps, loading game levels. Higher is better.

Storage capacity is measured in gigabytes (GB) or terabytes (TB). 1 TB equals 1,000 GB. For reference: a typical game is 50 to 100 GB, a 4K movie is around 50 to 80 GB, and a large photo library might be 200 to 500 GB. More capacity always costs more, but the price per GB drops as drives get larger.

A NAS is a dedicated device that stores files and shares them over your home or office network, like a personal cloud. NAS drives are built to run 24/7 and handle multiple simultaneous connections without failing prematurely. They are rated differently from desktop drives and should not be swapped with regular consumer drives in a NAS enclosure.

Sony's PlayStation 5 has an M.2 expansion slot for NVMe SSDs. The PS5 supports both Gen 3 and Gen 4 drives, but Sony recommends a sequential read speed of at least 5,500 MB/s to get the most out of it. A heatsink is also recommended. Some drives include one, others require you to add one separately.

High-speed NVMe drives, especially Gen 4 and Gen 5, generate significant heat under load. A heatsink is a metal fin that sits on top of the drive to dissipate heat and prevent thermal throttling, which is when the drive slows itself down to cool off. Some drives ship with a heatsink included, others need one added separately.

A portable drive is an external drive designed to be carried around. They are bus-powered with no separate power cable needed, compact, and usually shock-resistant. Ideal for photographers on location, remote workers, or anyone who needs their data on the go.