Portable SSDs are incredibly convenient, but are they as fast as the ones you can put inside your PC? The short answer is no, which is fine—they have their own use cases. But, if your portable SSD, often worth upwards of $100, is disappointingly slow, the drive itself may not be the cause.
The truth is that stars really have to align for a portable SSD to perform at its best, and if yours is underperforming, these are some of the possible roadblocks.
Portable SSDs can be fast, but they have their limits
There’s a difference between “fast” and “just as fast as regular SSDs”
Credit: Tim Rattray/How-To Geek
Comparing a portable SSD to a modern NVMe drive is like comparing apples to oranges. The gap grows even wider if you tend to buy one of the fastest SSDs, which can reach speeds of over 14,500MB/s.
You’re not going to see similar speeds on portable SSDs, but the drives aren’t really to blame here. Many factors come into play that either allow or disallow a drive from performing at its best, and because these SSDs connect via USB, they’re capped by more than just their own internal specs. Beyond that, they’re made for convenient, consistent performance, and the aim is always compatibility and efficiency rather than raw throughput.
A quick look through modern portable SSDs, such as the SanDisk Extreme pictured above, tells me that we can expect speeds up to 1,050MB/s. But some drives, like the Samsung T9, push the envelope and offer up to 2,000MB/s. Then, there’s the SanDisk Professional 4TB Pro that can go as high as 3,000MB/s, but that’s at an eye-watering $500 price tag. (Although, given the capacity, it’s not that bad a deal—a trend that spreads to SSDs as a whole.)
Those speeds don’t seem impressive when you compare them to the NVMes that end up in our PCs. Even PCIe Gen 3 drives, while a terrible deal right now, have those speeds beat. Gen 4 and Gen 5 are both miles ahead.
With that said, even the slower portable drives are adequate for what most people need. The problems start when they’re capped by something else entirely, and you’re paying for speeds that don’t materialize in real life.
Your SSD might not be the problem
Just like regular SSDs, portable drives rely on several outside factors.
Credit: Justin Duino / How-To Geek
The thing about external storage is that it’s only ever as fast as the entire chain connecting it to your PC (or any other device). That includes the SSD, the cable, the port, and the end device. Just one weak link can completely tank the 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 issue is that your drive isn’t actually running in its best mode. USB connections negotiate a speed and feature set when you plug something in, and if anything in the chain is subpar, the whole setup falls apart. Don’t get me wrong, it’ll work—it’ll just be a lot slower than it should be.
Unfortunately, USB ports are infamous for being confusing, and there’s often no easy way to tell whether your SSD is using the optimal port available.
Cables are another huge offender. Many USB-C cables are made primarily for charging, and some are limited to only basic data speeds. Again, they’ll still work, just very slowly, essentially wasting all that extra juice your SSD might be capable of. USB hubs can easily bottleneck a fast SSD, especially if it’s sharing bandwidth with other devices.
There’s also the protocol side of things. External SSDs can run using faster storage protocols, but on older protocols, performance can be disappointing, especially when you’re dealing with a boatload of smaller files.
In a way, your SSD is often the least of all problems. It’s really the USB side of things that you need to be looking at.
Using the right USB port is crucial
And that’s not always easy to do.
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Even a high-end SSD can never outrun the USB port it’s plugged into. As I mentioned above, the connector and the port both don’t tell you the speed at a glance, so you may only figure out whether 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 see 5Gbps, 10Gbps, 20Gbps, and 40Gbps USB ports regularly. But there are also different generations and types, including USB-A 2.0, 3.0, 3.1, and so on. Making sense of this mess is half the problem.
As a rough guide, a 10Gbps connection is usually where you will see those 900MB/s to 1,050MB/s SSDs do well in real-life file transfer tests. As such, buying a faster SSD if the port you’re using is 10Gbps is pointless, and both the drive and the port need to support those faster speeds for the advertised SSD speeds to become reality.
To hit up to 2,000MB/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 that you paid for.
It’s also worth noting that you’re unlikely to hit the maximum theoretical speed in real-world use, and this applies to all SSDs. The way we use our drives is vastly different from the testing environment they get benchmarked in.
How to make the most of your external SSD
Always look at the big picture.
Credit: Tim Rattray/How-To Geek
SSDs aren’t cheap right now, period. Portable or internal, it really hardly matters. Even SATA SSDs are overpriced, and NVMes are pretty much 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 shopping, but it’s hard to predict what devices you’ll be using your SSD with, so here’s what you can do to give it the most optimal circumstances:
- Use the cable that came with the drive first, or buy one that’s explicitly rated for the speed you need.
- Plug in directly while troubleshooting or transferring files. Avoid USB hubs.
- Try every port on your device once and keep the fastest one as your SSD port. Some USB-C ports can be slower than others, even on the same PC.
- Check what your SSD is actually capable of and match your expectations and hardware to meet those speeds.
- Avoid big transfers while your system is busy, as the PC at the end of the transfer can also become a bottleneck.
- Keep enough space on the drive. Filling an SSD up to full is a common mistake that can destroy performance, and portable drives aren’t immune to it.
Making sure all the different puzzle pieces fall into place should give you solid performance when using a portable SSD. Remember that a one-off slow transfer is not an issue, but if the speeds are consistently subpar, it’s time to investigate and check whether all the other hardware falls in line with your portable SSD.
