Carrying tens of gigabytes of data around? A job for an external SSD: small, fast and affordable. Which one can do that best, says the test! The days when external SSD were a luxury item for technology fans are long gone. This is also shown by the 18 test candidates: An SSD with 500 gigabytes of storage space is available from 60 euros, with 1 terabyte from 110 euros. That is enough for many users and they can look forward to much more speed and significantly less weight an external SSD is now much better than an external hard drive (HDD).
External SSD are super fast storage
USB has established itself as the connection for external SSD currently there are still three connection variants: Type A, B or C. Type C is becoming a universal connection, because the socket is smaller, twist-proof and offers more technical options, such as the Thunderbolt Technology to be installed. Currently only a few expensive professional models like the Samsung X5 use this. In addition, the USB port should have enough speed so that it does not slow down the SSD.
Be careful: USB technology is important
Three different fast variants of the USB standard are currently used for external SSD with a USB socket:
- USB 3.1 Gen1 / USB 3.2 Gen1: The data runs at a maximum of 5 gigabits per second (Gbps). This means that up to 600 megabytes per second can be transferred.
- USB 3.1 Gen2 / USB 3.2 Gen2: Doubles the speed up to 10 Gbps. This makes up to 1.2 gigabytes per second possible.
- USB 3.2 Gen2: The data flows at a maximum of 20 Gbps. Up to 2.4 gigabytes per second can be transferred.
Only two test candidates, the Seagate Firecuda Gaming SSD and the WD Black P50 Game Drive, have a super-fast Gen2x2 socket. But this is of little use in everyday life, because practically all current notebooks, PCs or tablets have a maximum of USB 3.2 Gen2 sockets on board. The new USB-4 standard does not yet exist for external SSD.
Full speed only from USB 3.1 Gen2
A fast socket on a PC or notebook USB 3.1 Gen2 (or USB 3.2 Gen2) is also required if the data is to flow at full speed with fast SSD. The benchmarks of the test programs used in the laboratory showed that the SSD with NVMe technology theoretically contain values of up to 1,007 megabytes per second. With more practical data transfer, it was still up to 795 megabytes per second. NVMe technology makes this significant leap in speed compared to older SSD possible: NVMe stands for non-volatile memory (meaning "non-volatile memory"), an internal interface for SSD. This means that more memory modules of an SSD can be addressed at the same time and thus faster.
The fastest SSD with NVMe was the WD Black P50, closely followed by the Sandisk Extreme Pro Portable and the Seagate Firecuda Gaming SSD . Even the slowest SSD with NVMe technology, the Intenso Portable SSD Professional, delivered up to 655 megabytes per second for data transfer and up to 735 megabytes for benchmarks. The NVMe SSD leave the cheaper models with older SATA technology far behind. An external SSD is significantly smaller than an external hard drive.
SATA: The technology is no longer up to date
The fastest SATA models packed up to 534 megabytes in the benchmarks; if they transferred data, it was up to 475 megabytes per second. The difference between benchmarks and data transfer is smaller with the SATA SSD than with the NVMe models. Why? The bottleneck here is the transmission technology. The built-in chips could work faster with some SSD, but the SATA technology simply doesn't allow any more. The speed advantage of the NVMe models is clearly noticeable for particularly large files. Videos with several gigabytes, extensive photo or music files were much faster through the cable.
The fastest SSD with NVMe, the Crucial X8 Portable, managed up to 418 megabytes per second, the fastest without NVMe, the Media Range External SSD, only a maximum of 297 megabytes. It goes without saying that this is noticeable when the user copies larger photo and video collections. With smaller files, however, the technology used does not play a major role. In the test there were big differences in speed in both camps, no SSD was really fast: a maximum of 10 megabytes per second flowed over the data cable. The SSD remained faster than other storage media such as SD cards or external hard drives.
NVMe: professional technology is becoming the standard
The test field clearly shows that the manufacturers have recognized the advantage of NVMe technology. For the larger SSD with 1 terabyte of storage space, four models with SATA technology and eight models with NVMe competed. In terms of size, the surcharge for the new technology is less significant. In the cheaper SSD with 500 gigabytes, the more expensive technology is more noticeable, so there are fewer models. And when they do, they are often almost as expensive as an SSD with 1 terabyte and SATA technology: The WD Black P50 costs around 120 euros with 500 gigabytes.
Smaller and lighter
An external SSD is faster than a conventional hard drive with a USB connection and much smaller and lighter. Hard drives in 2.5-inch format weigh between 170 and 230 grams, the lightest SSD in the test weighs just 42 grams. The faster SSD with NVMe technology are often a little heavier than SATA models. The reason: Manufacturers install heat sinks to better dissipate heat that is generated at full SSD speed. At Sandisk, for example, the weight difference between the Extreme Pro Portable and the Extreme Portable is 40 grams. The candidates are also compact: The smallest SSD in the test, the Media Range, fits easily in your pocket. But even the largest model, the WD Black P50, easily disappears into the jacket pocket.
The cable doesn't always fit
A perfect universal cable is unfortunately not included with an external SSD, because depending on which device the user wants to connect it to, cables of different lengths with different connections are required. A shorter cable is usually more practical for a notebook, but a longer cable for a desktop PC in a tower case if the SSD is to be on the desk. Also important so that the SSD is as versatile as possible: The manufacturer should consider both connection options, with a cable for devices with a USB-A port such as computers or TVs and a cable for devices with a USB-C socket such as tablets or the latest MacBooks.
Be careful with backups
If you use an external SSD for data backup, you have to be even more careful than with an external hard drive. The reason: SSDs store data more scattered than hard drives. In everyday life, this is not a problem thanks to the super-fast access, but it is a problem with data recovery, for example if the SSD was accidentally deleted or formatted. Rescue programs do not always manage to restore all data. Users should therefore save particularly important data on two SSDs so that the second, undamaged copy can be used in an emergency.
External SSD with USB port
Double victory for Sandisk in the external SSDs with conventional technology: The Sandisk Extreme Portable won in both sizes: 500 gigabytes and 1 terabyte. The fast SSD with NVMe technology were really tight: The WD Black P50 Game Drive just won. The Intenso Portable SSD Professional is the price-performance winner in this class. It is hardly more expensive, but significantly faster than an SSD with conventional SATA technology.