Solid-state drives have clear advantages over old-school hard-disk drives—they’re faster,
quieter, and consume less power.
But while choosing an SSD can seem complex, what with all the acronyms you’ll see when
looking at specs, it’s really quite simple--you just need to choose the right form factor
and speed for your situation.
Let’s tackle form factors first.
SSDs come in multiple shapes and sizes, but the two most common forms are 2.5” drives
and M.2 drives.
Each have their advantages: M.2 drives don’t require additional cables because they connect
directly to your motherboard, and some types are faster than 2.5” drives.
For their part, 2.5” drives are often cheaper.
Other less common form factors include PCIe add-in cards and U.2 drives, both of which
are used in in desktop PCs.
PCIe add-in cards connect to your motherboard using the same type of PCIe slots that a graphics
card or sound card does, while U.2 drives only work if a U.2 connector has been included
on the motherboard or you have an adapter to use it in an M.2 slot.
As you might guess, U.2 drives are the most rare form factor.
So how do you pick between the two main types?
(Again, that’s the M.2 and 2.5” form factors.)
Well, that depends on what your desktop or laptop can support.
For desktop systems with modern hardware or slightly older high-end hardware, you’ll
usually have your choice of both M.2 and 2.5” drives, so your building preferences and budget
(along with parts availability) will have more influence on your selection.
Many people don’t even choose between the two, and instead go with a combination—usually
M.2 for your boot drive and one or more 2.5” drives for tasks that would feel slow using
a more spacious hard-disk drive.
(That would be like gaming or video rendering.)
For older desktop systems, you’ll likely be stuck with just 2.5” drives as your option.
If you really want the faster speeds you can get with some M.2 drives, you can look at
PCIe add-in adapter cards, but you’ll need to first make sure the PCIe slots on your
motherboard are compatible.
As for laptops, if you can choose between SSD form factors when configuring a new notebook,
choose whichever option offers the best value and performance relative to the cost.
But with most laptops, you won’t get to decide.
For upgrades on older laptops, you also may not get a choice.
The laptop’s configuration may limit you to only one form factor.
To figure out if your model has an M.2 slot, a 2.5” drive bay, or both, you’ll need
to find its service manual online or do research on forums and Reddit.
You can also try contacting the manufacturer’s customer support.
Be sure to buy a drive compatible with your laptop—pay attention to details like interface
type (which I’ll cover in the next section) and the Z-height of your original 2.5” drive.
Also check reviews to find out the power consumption of any specific SSD you’re considering,
as it will have an impact on your battery life.
Now let’s move on to speed.
When an SSD is referred to as being a SATA or NVMe drive, you’re essentially hearing
shorthand for the speed range you can expect from it.
You see, not all SSDs use the same digital interface to transfer data.
Some still use serial ATA, or SATA, while newer models use the Non-Volatile Memory Express
protocol, or NVME protocol, over PCI Express.
SATA is older, and as you’d expect, SATA drives are slower than the NVMe variety.
But they’re still a huge improvement over a hard-disk drive—their average read and
write speeds fall in the range of 500MB per second, which is between three and six times
faster than a HDD.
For example, the S31 that we have here is rated at 560MB/s for read speed, 525MB/s for
write speed, and hit 562MB/s and 511MB/s, respectively, in our benchmark tests.
Combine that with affordable prices, and you have a great option for cost-conscious PC
builds and upgrades.
I now regularly recommend SATA SSDs to everyone buying a new PC, and especially so when doing
an upgrade on an old PC.
The performance boost over hard-disk drive is so substantial--even in mundane situations
like loading a website--that for most people, it feels like a completely different computer.
That said, NVMe drives are blazing fast compared to SATA drives, and it shows.
Right now, most NVMe drives are between 5 to 6 times faster than SATA drives, and a
newer variety currently tops out at around 10 times as fast.
As manufacturers refine their designs and release more models of that quicker variety,
the speed of NVMe drives will continue to climb the charts.
The terms you know when digging through specs for NVMe drives are PCIe Gen 3 (sometimes
written as PCIe 3.0) and PCIe Gen 4 (sometimes written as PCIe 4.0).
You’ll also want to note if they’re listed as being “by 2” or “by 4,” which will
be written out as “x2” and “x4” and refer to the number of PCIe lanes the drives
can use.
The more lanes, the more data the drive can transfer at one time.
Current PCIe Gen 3 “by 4” drives average speeds between 2500 and 3200MB per second
for reads and writes, while PCIe Gen 4.0 “by 4” drives average 5,000 MB per second.
The P31 that we have here as our example is a PCIe Gen 3 drive that’s rated at 3500MB/s
for read speed, 3200MB/s for write speed, and hit 3,521MB/s and 3,457MB/s, respectively,
in our benchmark tests.
If all that related to NVMe drives was simply too much acronym soup, just remember that
the bigger the numbers, the faster the drive should be.
Alright, so how do you choose?
Well, similar to form factor, you don’t always get to make that decision.
2.5” drives are all SATA drives.
And while M.2 drives come in both the SATA and NVMe varieties, what your motherboard
supports dictates what you should buy.
M.2 slots can support only SATA, only NVMe, or both.
In desktop PCs, you’ll see at least one slot on the board that supports both, and
sometimes a second one that either supports both or just SATA.
In laptops, it can be any one of those three scenarios, so you’ll need to find out your
specific model’s specs.
If you do get a say in the interface type, consider SATA drives as sufficiently quick
for everyday tasks and even gaming, and then NVMe as great for high-performing PCs where
it’s important to save time on large file transfers.
Overall, the age of your PC and your budget will help shape your decision.
And as a reminder, even if you’re restricted to only SATA or only NVMe drives, individual
SSDs vary in performance, which can affect your interactions with your PC.
So be sure to compare specs and read reviews.
Okay, last thing.
You may have read or heard about the types of NAND in SSDs, and might be wondering if
you need to worry about those different flavors of flash memory are.
For most people, the answer is no.
Most folks who buy an SSD don’t need to dig into the pros and cons of SLC, MLC, TLC,
and QLC drives.
What matters more is how the drive performs when doing different types of file transfers,
and you’ll see those results in individual reviews.
The same advice applies to DRAMless SSDs, or SSDs that lack a dynamic RAM cache.
While these budget SSDs can be slower in some aspects, they still outperform drives of pokier
interface type.
So a DRAMless NVMe drive is still faster than a SATA SSD, and a DRAMless SATA drive is still
faster than hard-disk drive.
If you’re worried about the performance disparities, look at the individual reviews,
but don’t feel like you have to stretch your budget to avoid a DRAMless model.
Only skip these when a specific model’s performance is obviously bad, is priced similarly
to one with a DRAM cache, or if you need more even performance across the board.
All right, so hopefully that helped clarify the alphabet soup you’ll encounter when
choosing an SSD.
If you’re looking for further information on individual drives, we review SSDs on our
website at PCWorld.com, which you can find the link for below.
We also have further SSD coverage and other tech explanations right here in our suggested
videos.
Otherwise, thanks for watching and I’ll catch you next time.