The hidden reason why your portable SSD is painfully slow

Portable SSDs are incredibly convenient, but are they as fast as the ones you can install in your PC? The short answer is no, which is fine: they have their own use cases. But if your portable SSD, which is often worth more than $100, is disappointing, the drive itself may not be the cause.

The truth is that the stars really have to align for a portable SSD to perform at its best, and if yours is underperforming, here are some of the possible obstacles.

Portable SSDs can be fast, but they have their limits

There’s a difference between “fast” and “just as fast as traditional SSDs”

Credit: Tim Rattray/How-To Geek

Comparing a portable SSD to a modern NVMe drive is like comparing apples to oranges. The gap widens even more if you tend to buy one of the faster SSDs, which can reach speeds above 14,500 MB/s.

You won’t see similar speeds on portable SSDs, but the drives aren’t really to blame here. Many factors come into play that allow or prevent a drive from performing optimally, and because these SSDs connect via USB, they are limited by more than their own internal specifications. Beyond that, they’re designed to deliver practical, consistent performance, and the goal is always compatibility and efficiency rather than raw throughput.

A quick look at modern portable SSDs, such as the SanDisk Extreme pictured above, tells me we can expect speeds of up to 1,050 MB/s. But some drives, like the Samsung T9, push the limits and offer up to 2,000 MB/s. Then there’s the SanDisk Professional 4TB Pro which can reach 3,000 MB/s, but at a whopping price of $500 $. (Although, considering the capacity, that’s not such a bad deal, a trend that extends across all SSDs.)

These speeds don’t seem impressive when compared to the NVMe found in our PCs. Even PCIe Gen 3 drives, while terrible at the moment, have superior speeds. Both Generations 4 and 5 are miles ahead.

That said, even the slowest portable drives meet most people’s needs. The problems start when they’re limited by something else entirely and you’re paying for speeds that don’t materialize in real life.

Your SSD may not be the problem

Just like traditional SSDs, portable drives depend on several external factors.

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The problem with external storage is that it’s only as fast as the entire chain connecting it to your PC (or any other device). This includes the SSD, cable, port, and end device. A single weak link can completely reduce transfer rates, and that’s precisely why you may see different performance on different devices, even when using the same SSD.

The most common SSD problem is that your drive isn’t actually operating in its best mode. USB connections negotiate a set speed and features when you plug something in, and if anything in the chain is subpar, the whole setup falls apart. Don’t get me wrong, it will work, it’ll just be a lot slower than it should be.

Unfortunately, USB ports are notorious for being confusing, and there’s often no easy way to know if your SSD is using the optimal port available.

Cables are another big offender. Many USB-C cables are primarily designed for charging, and some are limited to basic data speeds. Again, they will still run, very slowly, essentially wasting all the extra juice your SSD might be capable of. USB hubs can easily hamper a fast SSD, especially if it’s sharing bandwidth with other devices.

There is also the protocol side. External SSDs can work using faster storage protocols, but on older protocols performance can be disappointing, especially when you’re dealing with large numbers of smaller files.

In some ways, your SSD is often the least of the problems. It’s really the USB side of things that you need to look at.

Using the correct USB port is crucial

And it’s not always easy to do.

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Even a high-end SSD will never be able to outgrow the USB port it’s plugged into. As I mentioned above, the connector and port don’t tell you the speed at a glance, so you can only determine if you’re using the correct USB port through trial and error (and benchmarking).

Modern ports are often described by their maximum data rate in gigabits per second. You’ll regularly see USB ports at 5Gbps, 10Gbps, 20Gbps, and 40Gbps. But there are also different generations and types, including USB-A 2.0, 3.0, 3.1, etc. Making sense of this mess is half the problem.

As a guide, a 10Gbps connection is typically where you’ll see these 900MB/s to 1050MB/s SSDs succeed in real-world file transfer tests. As such, buying a faster SSD if the port you’re using is 10Gbps is pointless, and both the drive and port must support these faster speeds for the advertised SSD speeds to become a reality.

To achieve up to 2000MB/s, you’ll need 20Gbps support (often listed as USB 3.2 Gen 2×2). Otherwise, your SSD will behave like a 10Gbps drive and you’ll never see the speed you paid for.

It’s also worth noting that you’re unlikely to hit the theoretical maximum speed in the real world, and this applies to all SSDs. The way we use our drives is very different from the test environment in which they are compared.

How to get the most out of your external SSD

Always look at the bigger picture.

Credit: Tim Rattray/How-To Geek

SSDs aren’t cheap right now, period. Portable or internal, it hardly matters. Even SATA SSDs are too expensive, and NVMe is almost universally too expensive.

So, since you have a portable SSD, make the most of it. In an ideal world, you’ll check all the variables before making your purchases, but it’s difficult to predict which devices you’ll use your SSD with. Here is what you can do to offer him the most optimal circumstances:

• Use the cable that came with the player first, or buy one explicitly rated for the speed you need.

• Plug it in directly when troubleshooting or transferring files. Avoid USB hubs.

• Try each port on your device once and keep the fastest one as your SSD port. Some USB-C ports may be slower than others, even on the same PC.

• Check what your SSD is actually capable of and match your expectations and hardware to achieve those speeds.

• Avoid large transfers when your system is busy, as the PC at the end of the transfer can also become a bottleneck.

• Keep enough disk space. Fully filling an SSD is a common mistake that can destroy performance, and portable drives are not immune to it.

Making sure all the different pieces of the puzzle fall into place should give you solid performance when using a portable SSD. Remember, a one-time slow transfer isn’t a problem, but if speeds are consistently below average, it’s time to investigate and check if all other hardware is a match for your portable SSD.