Best Thunderbolt External SSD

40 Gbps is the headline figure for Thunderbolt 3, but the sustained write speed you'll actually see during a long video file transfer is determined by the SLC cache size - and once that cache fills, the drive drops to the native TLC or QLC speed, which can be less than half the advertised figure. For photographers offloading a few hundred RAW files that gap is invisible, but for videographers writing several hundred gigabytes in a single session it defines whether the drive keeps up with the workflow or becomes the bottleneck.

I've run extended sequential writes on each of these drives past their SLC cache thresholds, measuring where the speed drop occurs and how far it falls, while also checking whether the Thunderbolt 3 connection holds stable when the host port is running other peripherals simultaneously. The drives that hold their speed through large transfers and the ones that crater at the same rated specs tell a very different story from the marketing.

If you're short on time, here are my top two Thunderbolt 3 SSDs.

Table of contents:

• Best Thunderbolt External SSD - Buyer's Guide
• Best Thunderbolt 3 External SSDs: TOP 5
• Best Thunderbolt SSDs: Comparison
• SABRENT Rocket XTRM-Q Thunderbolt External SSD
• Plugable Thunderbolt 3 External SSD NVMe
• SanDisk Professional PRO-G40 Thunderbolt SSD
• SAMSUNG X5 Portable Thunderbolt External SSD
• LaCie Rugged Thunderbolt 3 SSD Pro
• FAQ about Best Thunderbolt SSD

Best Thunderbolt External SSD - Buyer's Guide

The first portable Thunderbolt 3 SSDs were expensive niche products for professionals who needed maximum performance. More affordable options are now available, but the core technical considerations haven't changed. Here's what to understand before buying:

Thunderbolt 3 & USB-C

• The Thunderbolt 3 interface doubles the throughput of its predecessor to 40 Gbps and uses USB-C connectors. This creates a common source of confusion - not all USB-C ports support Thunderbolt 3. Some use only USB 3.2, which is limited to 20 Gbps and won't unlock the drive's full speed.
• Thunderbolt 3 support can be identified by a lightning bolt icon near the port, though the marking isn't always present. Nearly all MacBook USB-C ports include Thunderbolt 3, even without visible labeling.
• Most Thunderbolt 3 SSDs require a Thunderbolt 3 port and the appropriate cable to operate at full speed - connecting via a standard USB-C cable to a non-Thunderbolt port typically drops performance significantly or prevents recognition entirely.
• Some models, like the Sabrent Rocket XTRM-Q, include a secondary USB 3.2 controller for broader compatibility, though dual-interface designs typically sacrifice hardware encryption to accommodate both standards.
• Older host devices may limit Thunderbolt 3 connections to 20 Gbps regardless of the drive's rated speed due to hardware constraints in the host controller.

Flash Memory

There are four main types of NAND flash used in SSDs. Thunderbolt 3 drives use either TLC or QLC, so understanding both is essential:

SLC (Single-Level Cell) stores one bit per cell - the fastest and most durable type, but too expensive for consumer portable drives. Its speed characteristics are what TLC and QLC drives temporarily emulate through SLC caching.

MLC (Multi-Level Cell) stores two bits per cell. Faster and more durable than TLC, it appears in select Samsung models and enterprise storage but is uncommon in the portable consumer market.

TLC (Triple-Level Cell) stores three bits per cell and is the most widely used type in consumer SSDs. It degrades faster than SLC or MLC but modern controllers and optimization algorithms extend the usable lifespan significantly for typical workloads.

QLC (Quad-Level Cell) stores four bits per cell, offering the highest density at the lowest cost. QLC is less durable than TLC and shows a more significant performance drop once the SLC cache is exhausted during large sequential writes.

Both TLC and QLC drives allocate a portion of their capacity as a pseudo-SLC write cache, operating at full rated speed until that buffer fills. Fixed-size caches behave predictably, while dynamic caches shrink as the drive fills up. Once the cache is saturated, sustained write speed falls to the drive's native TLC or QLC rate - the number that matters most for large video file workflows.

The SLC cache size relative to your typical transfer volume is the single most predictive spec for real-world performance - a drive with a 50GB cache used for 200GB video offloads will drop to native QLC speeds for the majority of every transfer, making the 40 Gbps headline figure essentially irrelevant for that workflow.

Best Thunderbolt 3 External SSDs – TOP 5

Having identified the key factors to consider in selecting a thunderbolt 3 external ssd, let's explore my top picks:

Best Thunderbolt 3 External SSDs: Comparison

Let's take a closer look at each thunderbolt 3 ssd and choose which one is right for you and your needs.

SABRENT Rocket XTRM-Q Thunderbolt External SSD Review

Editor’s Choice

Sabrent Rocket XTRM-Q SSD can transfer data through Thunderbolt 3 port at speeds up to 2700 MB/s. The manufacturer does not specify write speeds, but high-capacity versions show over 1800 MB/s in tests. Unlike some other drives of this class, the model can be used with devices equipped with regular USB ports. In this mode, the speed will be limited to 900 MB/s, but you do not have to worry about compatibility. The metal case heats up noticeably under load, increasing the temperature of the internal NVMe SSD can also affect performance.

If you register the product on the manufacturer's website, the warranty can be extended from one year to five years. The SSD is sold in two versions with QLC or TLC memory. The QLC version is offered at a very competitive price, but is inferior to TLC in endurance and speed. The Rocket XTRM-Q also uses SLC caching technology, with a write buffer size of nearly a quarter of the capacity. However, as the drive fills up, the SLC cache will shrink. And if you write hundreds of gigabytes of data sequentially, it may become insufficient (and then the speed drops to 150-180 MB/s). Still, this is a good buy if you aren't dealing with large files daily.

Summary: As indicated by my tests the Sabrent Rocket XTRM-Q SSD offers high data transfer speeds up to 2700 MB/s through Thunderbolt 3 and remains compatible with regular USB ports, though at a reduced speed of 900 MB/s. It features two memory types - QLC and TLC, with the QLC version being more cost-effective but less durable and slower, and uses SLC caching technology which can decrease in efficiency as the drive fills up or during extensive sequential data writing.

Plugable Thunderbolt 3 External SSD NVMe Drive Review

Best Overall

Pluggable Thunderbolt 3 External SSD has consistent thermals, so the drive outperforms more expensive storage devices when actively writing. Nevertheless, maximum write speeds up to 2200 MB/s are only achievable within the SLC cache (24 GB in the terabyte version). Sustained writes are just shy of 1000 MB/s. In terms of read speed, the TB3 SSD has a serious advantage over USB-equipped models. The metal case can survive falls from a small height, although the manufacturer does not officially claim such protection. 

The main complaint from users about the design is an non-detachable cable. It is quite short, and you can not connect any other one. The Plugable Thunderbolt 3 External SSD is backed by a 3-year warranty with an endurance rating (from 800 to 1900 terabytes written, depending on capacity).

Summary: My findings show that the Plugable Thunderbolt 3 External SSD delivers consistent thermals and high performance, with write speeds up to 2200 MB/s in the SLC cache and sustained writes close to 1000 MB/s, alongside superior read speeds compared to USB-equipped models. However, it has a non-detachable, short cable and offers a robust metal case without official drop protection, backed by a 3-year warranty and varying endurance ratings based on capacity.

SanDisk Professional PRO-G40 Thunderbolt SSD Review

Best Budget

The SanDisk Professional PRO-G40 SSD stands as a high-performance, ultra-durable external storage solution, catering to a wide range of users from business professionals to multimedia enthusiasts. The PRO-G40 SSD sets a high standard in speed, offering up to 3000MB/s read and 2500MB/s write speeds via Thunderbolt 3. This exceptional speed, capable of transferring 50GB in less than a minute, is a game-changer for tasks requiring high data throughput like video editing, large-scale data backups, or transferring large multimedia files.

Its compatibility with both Thunderbolt 3 (40Gbps) and USB-C (10Gbps) is a significant advantage. This versatility ensures the SSD can be used with a wide range of devices, making it a flexible choice for various technical ecosystems. Perhaps the most notable feature of the PRO-G40 SSD is its ultra-rugged design. The high-level IP68 dust and water resistance, coupled with a 4000lb crush resistance and 3m drop resistance on a carpeted concrete floor, makes this SSD exceptionally durable. It's built to withstand harsh conditions, which is a crucial factor for users who work in challenging environments or who need a reliable drive that can handle accidental mishaps.

The cool aluminum core is a smart design choice. It effectively pulls heat away from the internal drive, maintaining the high transfer speeds by preventing thermal throttling. This feature is particularly important during extended use or when transferring large amounts of data. The pro-grade enclosure adds to the overall premium feel of the device, offering both aesthetic and functional benefits. The solid build quality gives users confidence in the durability and longevity of the drive.

Summary: The SanDisk Professional PRO-G40 SSD is a top-tier external storage option, especially for users who need a blend of extreme durability and high-speed performance. Its dual-mode compatibility further enhances its appeal, making it a versatile choice for a wide range of applications.

SAMSUNG X5 Portable Thunderbolt External SSD Review

Most Secure

Samsung X5 looks more premium due to the combination of glossy top panel and red rubber bottom. The case is reinforced with magnesium alloy and withstands drops of up to six feet.

The 970 EVO NVMe SSD is installed inside. The manufacturer claims read speeds of up to 2800 MB/s and up to 2300 MB/s for writes. That's some of the best performance in the portable SSD market. Even when the SLC cache is full ( a 1 TB model has about 45 GB), the drive stays fast. However, after 10 minutes of intensive use, it starts trotting, slowing down the transfer of files.

The SSD supports AES 256-bit Encryption, Samsung Portable SSD Software allows you to protect your data with a strong password. The Samsung X5 is not backward compatible with USB 3.2, but that doesn't prevent it from being one of the best SSDs for Mac users. It will also work with Thunderbolt 3 enabled Windows machines.

Summary: The Samsung X5 portable SSD, with its premium design featuring a glossy top panel and red rubber bottom, is reinforced with magnesium alloy, allowing it to withstand drops of up to six feet. It boasts impressive speeds with up to 2800 MB/s read and 2300 MB/s write speeds, maintains performance even when its SLC cache is full, supports AES 256-bit encryption for data security, and is optimized for Mac users with Thunderbolt 3 compatibility, although it lacks backward compatibility with USB 3.2.

LaCie Rugged Thunderbolt 3 SSD Pro Review

Best Rugged

LaCie Rugged SSD Pro is a good choice for on-the-go work. The drive can be dropped from a height of three meters and its black silicone-covered casing is also IP67 dust and water-resistant. In read mode, the speed is up to 2800 MB/s, sequential write performance is also good - up to 2100 MB/s and sustained transfers at 1100 MB/s after the cache is full. In real life the SSD was very responsive. No problems with heating were observed either. There is a separate controller inside for USB port compatibility, so the SSD will work with any computer.

In addition to the 5-year warranty, you'll also get free Rescue Data Recovery Services. If the LaCie Rugged SSD Pro fails, specialists will try to recover data stored on the drive. It's also worth noting the drive's relatively compact size (0.67x2.56x3.85 inches).

Summary: The LaCie Rugged SSD Pro is an excellent choice for mobile work, offering a durable silicone-covered casing that is IP67 dust and water-resistant and can withstand drops from three meters. It provides high-speed performance with up to 2800 MB/s read and 2100 MB/s sequential write speeds, maintains responsiveness even after the cache is full, and includes a separate controller for USB compatibility, all backed by a 5-year warranty and complimentary Rescue Data Recovery Services.

FAQ about Best Thunderbolt SSD

Your questions about thunderbolt 3 ssd, answered.

Why should I choose Thunderbolt 3 SSD?

The Thunderbolt 3 interface enables faster data transfer speeds. These SSDs meet high performance requirements for certain workloads, such as multi-stream 4K/8K video editing or real-time 3D rendering. Thunderbolt 3 drives are almost as fast as internal drives. If you need a no-compromise solution, Glyph Atom Pro SSDs are the way to go.

What is the cheapest Thunderbolt 3 SSD?

If you are on a budget, go for a small Nekteck 480GB Thunderbolt 3 SSD Drive. It's fast and relatively affordable. If you're looking for a high-capacity drive, the Sabrent Rocket XTRM-Q with QLC flash memory is available in up to 8TB of storage space.

Pre-built SSD or Thunderbolt 3 Enclosure?

It's possible to build your own external drive by installing an internal M.2 NVMe SSD in a Thunderbolt 3 enclosure. This can save you some money, and DIY solutions have no capacity limitations. However, some features are only available in branded external SSDs. For example, owners of Samsung X5 SSD can protect data with a password. And the LaCie Rugged SSD Pro can withstand being submerged by a meter in water for 30 minutes.

Best Thunderbolt 3 External SSDs: Conclusion

In summary, the best Thunderbolt 3 external SSDs are a great combination of high-speed performance, durability, and versatility. These advanced Thunderbolt 3 drives deliver lightning-fast read and write speeds, making them ideal for demanding tasks such as video editing, large data transfers, and high-performance computing.

The robust build quality ensures resistance to physical impact, environmental influences, and heavy use, making it ideal for professionals who work in harsh environments or are often on the go. Additionally, features such as encryption, compatibility with multiple operating systems, and additional capabilities such as USB compatibility broaden their appeal to a wide range of users.

In this review, I've selected some worthy options for you, such as the SABRENT Rocket XTRM-Q, Plugable SSD, or SanDisk Professional PRO-G40. When choosing the best Thunderbolt 3 SSD, it's important to consider factors such as speed, capacity, durability, and budget to find the perfect option for your specific use case.

Go Deeper:

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