SSD vs. HDD: What's the Difference?

Side-by-sideWritten comparisonAll comparisons

Read the comparison below, or explore it visually. Create a visual lesson comparing ssd and hdd using available credits or plan allowance.

An SSD (solid-state drive) stores data in flash memory chips with no moving parts, while an HDD (hard disk drive) stores it magnetically on spinning platters read by a moving head. That difference makes SSDs many times faster, silent and more resistant to knocks, while HDDs still give more storage for the money, which suits large backups and archives.

At a glance

	SSD	HDD
How data is stored	Electric charge in NAND flash memory cells	Magnetic patterns on spinning platters
Moving parts	None	Platters spin, often at 5,400 or 7,200 rpm
Speed	About 500 MB/s (SATA) to several GB/s (NVMe)	About 100 to 250 MB/s for large files
Cost per gigabyte	Higher	Lower, especially at multi-terabyte sizes
Durability	Survives drops well; cells wear after many writes	Shock-sensitive while running; mechanical parts wear

Which should you use?

SSD

Choose an SSD for the drive that holds the operating system and apps: a laptop with an SSD typically boots in seconds and opens programs far faster than one with a hard disk.

HDD

An HDD suits bulk storage where speed matters less, such as a multi-terabyte external drive for backing up family photos or a CCTV recorder writing video around the clock.

Frequently asked questions

How long does an SSD last?

For typical home use, most SSDs last many years. Flash cells wear out after a limited number of writes, so makers give an endurance rating in terabytes written (TBW), and ordinary users rarely reach it before they replace the computer.

Can I replace my laptop's hard disk with an SSD?

Usually, yes. Most laptops with a 2.5-inch hard disk accept a 2.5-inch SATA SSD, and many newer ones have an M.2 slot. You then clone the old drive or reinstall the operating system. The laptop's manual lists the supported drive types.

Why is an SSD faster than an HDD?

An HDD must spin the platter and move its head to the right track before each read, which takes several milliseconds. An SSD reads flash cells electronically in microseconds and can access many memory chips in parallel.