Best Portable SSDs: Holiday 2023

Once the domain of external, bus-powered hard drives, these days the market for external storage has been almost completely consumed by portable SSDs. Rapid technological advancements in NAND flash technology (including the advent of 3D NAND) has allowed their capacity to eclipse 2.5-inch HDDs, all the while multiple improvements in host interface speeds (such as the move from USB 2.0 to 3.0, and onwards to 3.2 Gen 2 / Gen 2×2 / USB4) has made portable SSDs faster and more reliable than the hard drives they replace. All of which has helped to make portable SSDs the go-to solution for external storage, both big and small.

2023 Q4 PSSD Introductions
Samsung T5 EVO USB 3.2 Gen 1 PSSD (Left), ADATA SE920 USB4 PSSD (Right)

Recent product introductions in this segment point to the market demand for compact high-speed PSSDs with a low power consumption profile. Multiple vendors have introduced USB 3.2 Gen 2 / Gen 2×2 ‘SSD-in-a-stick’ models based on native flash controllers. On the other hand, established vendors are pushing the boundary with ultra-high capacity options and true 40 Gbps USB4 PSSDs.

New ‘SSD in a Stick’ Models from 2H 2023

Consumer requirements in the portable SSD market vary greatly. At the entry level, we have folks taking a step up from thumb drives for backing up their data or transferring files from one system to another. Short bursts of high speed, low power consumption for extending host battery life, and multiple capacity options are important here. Performance consistency under sustained stress is not a factor. In the mid-range, we have casual gamers and amateur content creators. While they require a certain level of performance consistency guarantee under sustained traffic, SLC cache sizes in the 40 – 100 GB range are often enough for that purpose. At the top end, we have professionals in the content creation industry, IT workers, and tech-savvy consumers. This demanding segment expects high-end internal SSD performance in their PSSDs for backing up data in the field, running portable operating systems across multiple computers, and transferring large amounts of data between different systems frequently. PSSDs with DRAM for the flash translation layer and / or those with high-end transfer rate specifications (USB 3.2 Gen 2×2 / Thunderbolt drives) are suitable for such use-cases.

The tuning of this PSSD guide is based on multiple factors. The obvious one is the speed rating / host interface connection protocol. At the lowest end, we have USB 2.0 thumb drives – but those are not the focus of this guide. For our purposes, the entry level is the 500 MBps-class. On the left of this, we have USB 3.2 Gen 1 ( 5 Gbps ) drives like the Samsung T5 EVO family. On the right, we have families like the Crucial X6. It is a USB 3.2 Gen 2 ( 10 Gbps ) drive, but the 500 GB model employs a SATA SSD behind the Gen 2 bridge, capping it at 540 MBps. The other capacities use the Phison U17 native flash controller. While it also has a USB 3.2 Gen 2 upstream interface, the controller characteristics and use of QLC NAND restrict them to sub-800 MBps speeds even under the best of conditions. At the highest end, we have the 2.5 GBps-class Thunderbolt 3 drives. Between these two extremes, vendors have provided consumers with multiple options for 1 GBps-class, and 2 GBps-class PSSDs.

Another factor influencing consumer choice is the physical size of the PSSD. Some scenarios dictate the use of a thumb drive, and thanks to technological advancements, we now have affordable high-performance SSDs in that form-factor.

There is always a trade-off between performance and power consumption in any computing category, and PSSDs are no exception. Bridge-based solutions provide more flexibility and, depending on the SSD behind it, can provide better performance compared to native flash controllers (which are almost always DRAM-less). However, the latter has the advantage of lower BOM cost (translates to lower consumer pricing). Replacing a two-chip solution (SSD controller + bridge) with a single native flash controller brings power consumption benefits as well. This may also influce consumer choice while selecting a PSSD for purchase.

The type of NAND in the PSSD is yet another factor, with consumer QLC to be avoided for write-intensive and sustained performance-sensitive use-cases. However, the same QLC can be a cost-effective choice for entry-level PSSD workloads where consumers are migrating from either thumb drives or external hard drives.

For our guide, we are narrowing down the vast field of PSSDs into a few select product lineups. These are the ones which we have analyzed in great detail – either through hands-on review, or as part of their launch coverage. If there are any PSSD models from the top tier vendors that you would like us to consider for future guides, a mention in the comments will place them in our review consideration queue.

Aspects of Interest

Almost all of the PSSDs considered in this buyer’s guide have been subject to hands-on review. The relevant links along with other aspects of interest are provided in the table below.

The above table also lists some of the key consideration aspects that are usually not part of the marketing specifications. For example, if frequent usage with a mobile device is a use-case, it is important to choose a low-power option. PSSDs employing native UFD controllers almost always win on this metric over bridge-based solutions. Some use-cases may preclude the possibility of utilizing a separate cable. For such scenarios, one of the ‘SSD-in-a-stick’ models may be the optimal choice. QLC-based options should be avoided for write-heavy use-cases. Users planning to run a portable OS on their portable drive may be better off using PSSDs with DRAM built in for the flash translation layer – that greatly helps with small-sized random disk accesses common in such use-cases.

Pricing Matrices and Concluding Remarks

Multiple pricing matrices are provided below based on the speed class of each PSSD family. Readers who have already decided upon the host interface type for their PSSD can narrow down their options based on the relevant table.

Crucial was one of the first vendors to release a mainstream PSSD with QLC in the late 2010s. Vendor confidence in QLC has been improving steadily in the last few years. Solidigm even has an enterprise line based on QLC flash. On the PSSD front, Samsung joined the QLC fray recently with the launch of the T5 EVO. It is currently the sole choice for a compact 8 TB PSSD from a tier-one vendor. There is a narrow set of use-cases where consumers would be willing to pay a huge premium for a unique product that sacrifices plenty on the performance table. The Samsung T5 EVO at $650 is the only choice for such use-cases.

Products such as the Transcend ESD310C and the OWC Envoy Pro Mini serve their own unique niche. These ‘SSD-in-a-stick’ products are compact, but still carry both Type-A and Type-C ports. The OWC model at $120 ( $114 w/ coupon ) has a more pleasing case design and is more rugged, which is why it carries a bit of a premium over the Transcend one at $85. There are more options coming in this dual-interface segment, but these two are the currently recommended ones in the category.

For the absolute best performance, the SanDisk Professional PRO-G40 in Thunderbolt mode with write caching turned on delivers the goods. It is also compatible with legacy USB ports as a 1 GBps-class drive. At 10 ¢ / GB, the capabilities are going to cost a pretty penny. Pure Thunderbolt drives may offer better performance, but it has been quite some time since we saw one in the market. With USB4 in the picture, the envelop for the top category is getting pushed. ADATA is promising speeds as high as 3.8 GBps in the new SE920. The thermal solution is a challenge, and we will see how it plays out with tier-one vendors next year.

Overall, we see Crucial’s PSSD lineup delivering good value for money across multiple categories. The current downturn in the flash market has been good for consumers, but the cyclic nature of the industry may soon bring back cheer to the flash vendors.