An SSD (solid state drive) stores data on flash memory chips with no moving parts. An HDD (hard disk drive) stores it on spinning magnetic platters read by a moving arm. That single difference explains almost everything else: why SSDs boot a computer in seconds, why hard drives are still cheaper for bulk storage, and why a laptop with a hard drive feels slow no matter how good its processor is.
Key takeaways
- SSDs have no moving parts, so they start programs and Windows far faster than a hard drive.
- A SATA SSD is several times faster than a typical hard drive, and an NVMe SSD is faster again.
- Hard drives still cost less per gigabyte, which makes them good for backups and archives.
- SSDs suit laptops better because they use less power and handle bumps.
- Every laptop and desktop we sell already runs on an SSD.
SSD vs HDD at a glance
| SSD | HDD | |
|---|---|---|
| How it stores data | Flash memory chips | Spinning magnetic platters |
| Typical sequential speed | About 500MB/s (SATA) to several thousand MB/s (NVMe) | Roughly 100 to 200MB/s |
| Boot and app loading | Seconds | Noticeably slower, especially from cold |
| Noise and heat | Silent, runs cool | Audible spin and clicks, warmer |
| Shock resistance | High, no moving parts | Low, a drop while running can damage it |
| Cost per gigabyte | Higher | Lower |
| Best use | The main drive in any computer | Backups, archives and large media libraries |
Why an SSD feels so much faster
Headline transfer speeds only tell part of the story. Everyday work is mostly thousands of tiny reads: Windows loading files at start-up, a browser opening its cache, Outlook searching mail. A hard drive has to physically move its arm to each piece of data, which takes milliseconds every time. An SSD reads from any location almost instantly. That is why swapping a hard drive for an SSD makes an older laptop feel like a different machine, often more than a processor upgrade would.
SATA SSD vs NVMe SSD
| SATA SSD | NVMe SSD | |
|---|---|---|
| Connection | SATA, the same as a hard drive | PCIe lanes on an M.2 slot |
| Typical maximum speed | About 550MB/s | About 3,500MB/s (PCIe 3.0) to about 7,000MB/s (PCIe 4.0) |
| Day-to-day feel | A big step up from an HDD | Faster again with large files, similar for light office work |
| Fits | 2.5-inch bays and some M.2 slots | M.2 slots that support NVMe |
For email, documents and browsing, the jump from a hard drive to any SSD is the one you will notice. The extra speed of NVMe matters most when you copy large files, edit video or load big projects.
Reliability and lifespan
Hard drives tend to fail mechanically: bearings wear, heads crash or the drive is knocked while spinning. SSDs have no moving parts but their flash cells wear slowly with writes. Each SSD carries an endurance rating, usually in terabytes written (TBW), and normal office or home use rarely comes close to it within the life of the computer. Our guide to checking SSD health shows how to see how much life a drive has left.
When a hard drive still makes sense
- Backing up a computer to an external drive.
- Storing large photo, video or music libraries you do not open every day.
- Network storage (NAS) and servers that need several terabytes at low cost.
- Keeping old project archives that only need occasional access.
A common setup on a desktop is an SSD for Windows and programs, plus a larger hard drive for bulk files. Compare current stock in our refurbished SSDs and refurbished hard drives.
Should you upgrade your current computer?
If your laptop or desktop still runs Windows from a hard drive, an SSD is almost always the best upgrade for the money. We cover the practical side, including what fits which model, in should you upgrade a laptop to an SSD. If you would rather skip the job, our refurbished laptops and desktops all ship with an SSD fitted, genuine Windows Pro and a 1-year warranty.
Frequently asked questions
Is SSD better than HDD?
For the drive your computer runs from, yes. An SSD is faster, quieter, uses less power and handles knocks better. An HDD is only better on price per gigabyte for bulk storage.
Does an SSD last as long as a hard drive?
For normal use, yes. SSDs wear slowly with writes, but their rated endurance is far beyond what typical home and office use reaches in the life of a computer.
Can I replace a laptop hard drive with an SSD?
Usually. A 2.5-inch SATA SSD fits the same bay as a laptop hard drive, and many laptops also have an M.2 slot. Check your model before buying.
What does SSD stand for?
Solid state drive. It is called solid state because it has no moving parts.
The short version: run your computer from an SSD, and keep hard drives for the cheap, bulky storage jobs where speed matters less.

