SSD vs HDD: Know the Difference

It’s time for SSD vs HDD: know the difference! We’ve been covering varieties of SSD technology for quite a while here on CGDirector, so it was only a matter of time before we eventually covered HDDs as well with more than just some passing mentions.

Stick around and I’ll be explaining all you need to know about the differences between SSDs and HDDs, and even discuss a few use cases you may not expect.

What is an HDD?

First, let’s talk about what an HDD actually is. HDD stands for “Hard Disk Drive”, and refers to a storage drive boasting a solid enclosure and 2-5 spinning disc-shaped “platters” within, hence the name.

HDDs read to and write from these platters at speeds according to their “RPM”, or Rotations Per Minute.

HDDs are among the oldest types of storage technologies used in PC hardware, and to this day still see frequent use.

However, they are beginning to get phased out and replaced more and more by SSDs in most PCs and many servers, for reasons we’ll dive into a little bit later.

What is an SSD?

SSD stands for “Solid State Drive”, and is named as such for its lack of moving parts compared to a traditional HDD.

Since SSDs don’t rely on moving platters, their speeds are measured in raw throughput rather than RPM.

Additionally, SSDs are constructed in such a manner that they’re much smaller than HDDs, with a reduction in size having no real compromises to performance or stability compared to shrinking an HDD.

I’ll dive deeper into the differences below, but now you understand the gist of it. HDDs are built around spinning disks, and SSDs are built around static NAND flash memory, with no moving parts to speak of.

SSD vs HDD: Know The Difference

SSDs Perform Faster Than HDDs

So, one of the first things to know about SSDs compared to HDDs is that they’re considerably faster.

Consumer 7200 RPM HDDs are typically not going to exceed more than ~150 MB/s or so of sequential read/write speed.

Now, there are some ways to break beyond this barrier with SSHDs, RAID setups (but this doesn’t actually increase read/write speeds per drive) or a certain super-expensive drive manufactured solely for data centers, but that has been the accepted limit of HDD storage for quite a while now.

Meanwhile, SSDs using the same SATA connector as an HDD can reach ~550 MB/s in read/write speed, thoroughly outclassing HDDs to the point where modern SSDs no longer even use the same connector.

The HDD vs SSD speed battle was won a long time ago in favor of SSDs— now, the storage speed battle is pretty much just between SSDs themselves on the NVMe standard, but more on that a little later.

SSDs Are Less Likely To Break Than HDDs

Another point in favor of SSDs is that they’re actually less likely to break than HDDs!

Remember: HDDs are comprised of moving parts.

Even when powered off, those parts need to be kept in stasis and not rattled or dropped so as to prevent damage to the fragile read/write header and especially the platters within the drive enclosure. And when HDDs are in use, their moving parts are prone to wear/tear and any sort of mechanical defects.

Since SSDs have no moving parts, you pretty much don’t have to worry about them being damaged due to physical shock unless you’re actively trying to break one of them.

Dropping a portable HDD can easily spell death for the drive if you don’t have a strong, padded enclosure protecting it. Dropping a portable SSD is a non-issue in comparison.

SSDs Last Longer Than HDDs

Another point in favor of SSDs is that no moving parts mean that they basically don’t have wear and tear, at least not in the sense that HDDs do.

Make no mistake, though: an SSD isn’t necessarily built to last forever. In fact, certain SSDs have shorter lifespans than others due to how they are built.

Any SSD is going to have a fixed number of write cycles it can endure before it begins to fail, but barring some early-gen SSDs with terrible reliability, this isn’t generally an issue for the end consumer.

The only time I would seriously worry about an SSD having a shorter lifespan than an HDD is if you were to get a QLC Flash-based SSD and use it in an editing or server environment, where the low write capacity of QLC would cause the drive to fail much sooner than a TLC Flash-based SSD or an HDD.

To summarize, a consumer-grade HDD is expected to last about three to five years of constant use before it fails due to mechanical wear and tear.

A consumer-grade SSD is expected to last ten years but could fail sooner if you manage to wear out its capacity of writes prior to then, which is generally unlikely.

HDDs Are Cheaper Per-Gigabyte Than SSDs

The story isn’t all bad for HDDs, though.

HDDs are still considerably cheaper for their capacity than SSDs are, even cheap SSDs.

According to Amazon AWS, HDDs only cost about three to six cents per gigabyte, whereas SATA SSDs eight to ten cents per gigabyte and more if you’re looking to buy a faster M.2 NVMe SSD.

If all gigabytes are the same to you, and they sometimes can be for certain workloads (more on that later), the price differential between SSDs and HDDs is heavily skewed in favor of HDDs.

That massive increase in storage speed isn’t free, and until the past two decades, it used to be so expensive that only the most dedicated professionals and enterprise consumers could afford SSD storage at all.

SSD pricing is much more accessible to consumers today, hence their wider adoption. But it wasn’t too long ago that you’d be paying the same price for a 256 GB SSD that you could instead pay for a 2TB HDD.

SSDs Come In Major Tiers of Speed

Finally, the last major difference between HDDs and SSDs is that modern HDDs are very…streamlined.

There are only three major HDD manufacturers, and most of them run at about the same speed on top of that unless you opt for a smaller, slower 5400 RPM HDD instead of a 7200 RPM HDD.

The SSD market has much more competition, though.

SATA SSDs have begun to standardize in about the same place due to the limitations of the SATA connector being reached relatively quickly, but M.2 NVMe SSDs that use PCI Express bandwidth also exist. And yes, PCI Express is orders of magnitude faster than SATA.

Note: PCIe 5 Speeds can be higher than indicated in this graph, and are mostly limited by the controller right now

For those unfamiliar, PCI Express is by far the fastest connector on any motherboard. And it gets refreshed semi-frequently.

Each new generation of the PCIe standard sees yet faster NVMe drives as a direct result, and even the first generation of NVMe SSDs— with PCIe Gen 3— started at full Gigabytes per second of transfer rather than “mere” hundreds of Megabytes.

FAQ

Are External SSDs Worthwhile?

External SSDs aren’t quite as blistering fast as internal SSDs, but I’d say they’re the better overall choice of an external drive than an external HDD since HDDs are slower and more prone to failure due to physical shock.

Alex has also written a more detailed guide to Internal vs External SSDs if you’re interested in learning more about them.

Are HDDs Bad?

Not at all!

Make no mistake: SSDs have many advantages over HDDs…but there are still a few use cases for HDDs where an SSD is pretty much just spending extra money for no reason.

The best use case for an HDD today is actually in media streaming, especially movies and TV shows. As it turns out, HDDs are more than fast enough for playback of even 4K HDR media without any real issue.

Text files, music files, shows, and movies should all work perfectly fine off an HDD, so for stuff like media backups or an HTPC (Home Theater PC), an HDD is still a pretty good choice.

The shortcomings of HDDs come into play with PC boot times, game load times, and any kind of heavy-duty file transfer or video editing workload.

I especially don’t recommend HDDs to a video editor, since timeline editing speed will be considerably worse on an HDD.

Workstations and gaming PCs are still best-served by an SSD, and even casual desktop use will be greatly improved with the OS and applications loading off an SSD.

When Should I Get an HDD Instead of an SSD?

Pretty much, I would only consider an HDD in today’s market for storing and streaming your personal media collection.

For gaming, editing, and other workstation applications, an SSD is better in every way except cost-per-gig.

Before SSDs were as cheap as they are today, it was common practice to get a small SSD “boot drive” for your operating system and maybe a few of your favorite games and a large HDD for everything else.

If you can’t afford a larger SSD but still want more storage capacity, I recommend taking this hybrid approach for a decent experience, since HDDs are still much slower for desktop use than an SSD.

Over to You

And that’s it, for now!

I hope this article definitely settled the matchup of SSD vs HDD for you. Now you should know the difference, and maybe I even managed to show some of you the more redeeming use cases for HDDS beyond just being cheaper storage.

Have any other questions about PC storage or PC hardware in general? Feel free to ask them in the comments section below, where me or another member of the CGDirector Team will be happy to help you.

Otherwise, consider heading over to our Forums to have longer-form engagements with the rest of our community of Enthusiasts and Experts.

Until then or until next time, happy building! And remember: you don’t need an SSD for watching movies, just making them.