External SSDs with a Thunderbolt 3 interface are still the only option for users looking to get high-end performance in a bus-powered portable device. These SSDs have become possible due to the emergence of NVMe drives in the compact M.2 form-factor, which are fully capable of saturating the Thunderbolt 3 interface, never mind slower interfaces like 10Gbps USB 3.x.

The TEKQ Rapide was one of the first Thunderbolt 3 external SSD that we reviewed. Since it was fairly easy to disassemble, we also presented some benchmarks of a DIY Thunderbolt 3 SSD using the TEKQ enclosure and a SanDisk Extreme Pro M.2 NVMe 3D SSD. Now, since we happen to have Western Digital's WD Black SN750 SSD in, we decided it would be interesting to take a look at the new drive in a similar scenario.

Introduction

The TEKQ Rapide is a 98mm x 45mm x 12mm silver-colored external SSD with an aluminum chassis. It sports a single Thunderbolt 3 interface for both power and data. The port is enabled by the Intel DSL6340 Thunderbolt 3 Controller - note that this belongs to the Alpine Ridge family, and hence, works only with Thunderbolt 3 Type-C ports. On the other side of the DSL6340 is a PCIe 3.0 x4 connection that leads to a M.2 slot capable of accommodating M.2 2260 or 2280 PCIe SSDs. There are no plastic components in the chassis.

There is nothing preventing advanced users from installing their own M.2 PCIe SSDs in the internal M.2 slot. The device is easy to disassemble, with four screws hidden under the rubber feet on the underside of the chassis. We took out the internal SSD (a Phison E7 reference design with Toshiba's MLC NAND) and replaced it with a 1TB version of the Western Digital WD Black SN750 M.2 NVMe SSD. The TEKQ Rapide enclosure includes thermal pads for both the M.2 SSD and the Thunderbolt 3 controller.

As a refresher, the WD Black SN750 uses Western Digital's in-house controller and couples it with 64-layer BiCS 3D TLC flash. While the SSD itself claims transfer rates of 3470 MBps reads and 3000 MBps writes, the extent of throttling introduced by the TEKQ enclosure is not immediately evident.

Benchmarks

Various synthetic benchmarks are available to quickly evaluate the performance of direct-attached storage devices. Real-world performance testing often has to be a customized test. We present both varieties in this review, starting with the synthetic benchmarks in this section. Prior to covering those, we have a quick look at our testbed setup and testing methodology.

Testbed Setup and Testing Methodology

Evaluation of DAS units on Windows is done with the testbed outlined in the table below. For devices with a Thunderbolt 3 (Type-C interface) connections (such as the DIY TEKQ Rapide - WD Black SN750 TB3 SSD 1TB that we are considering today), we utilize the USB 3.1 Type-C port enabled by the Intel Alpine Ridge controller. It connects to the Z170 PCH via a PCIe 3.0 x4 link..

The full details of the reasoning behind choosing the above build components can be found here. The list of DAS units used for comparison purposes is provided below.

• DIY TEKQ Rapide - WD Black SN750 TB3 SSD 1TB
• DIY TEKQ Rapide - SanDisk Extreme Pro TB3 SSD 1TB
• MyDigitalSSD Pocket Vault Express (PVX) 1TB
• Patriot Evlvr TB3 SSD 1TB
• Samsung Portable SSD X5 1TB (NTFS)

ATTO and Crystal DiskMark

Western Digital claims read and write speeds of 3470 MBps and 3000 MBps respectively, but our standard ATTO test trasnfer sizes and lengths do not back up those numbers. In fact, these numbers are very close to what we obtained with the SanDisk Extreme Pro SSD. In any case, these access traces are not very common in real-life scenarios.

Drive Power Consumption - CrystalDiskMark Workloads

DIY TEKQ Rapide - WD Black SN750 TB3 SSD 1TBDIY TEKQ Rapide - SanDisk Extreme Pro TB3 SSD 1TBMyDigitalSSD Pocket Vault Express (PVX) 1TBPatriot Evlvr TB3 SSD 1TBSamsung Portable SSD X5 1TB (NTFS)

It is interesting to note that the SanDisk Extreme Pro has many peaks close to the 8W mark, while the WD Black SN750 tops out around 7.8W, and that too, only very briefly.

Moving on to the pricing aspect, the most cost-effective TB3 1TB SSD is currently the Patriot Evlvr, but it comes with a PCIe 3.0 x2 NVMe SSD internally. Our DIY configuration (taking out the cost of the internal SSD from the lowest-priced TEKQ Rapide) comes next, which is a huge surprise given the gulf in performance compared to the other SSDs that we are comparing against.

The 1TB WD Black SN750 is retailing for around $250. We may soon have standalone Thunderbolt 3 SSD enclosures from TEKQ for around $162 to aid the DIY community, but that is not the pricing assumed in the table below.

Coming to the business end of the review, the WD Black SN750 makes for an excellent Thunderbolt 3 SSD. Despite only being a firmware upgrade to the SanDisk Extreme Pro M.2 NVMe 3D SSD / 2nd Gen WD Black NVMe 3D SSD (2018), the drive delivers key performance improvements for typical direct-attached storage workloads. In fact, our tests show that the configuration manages to surpass many off-the-shelf Thunderbolt 3 SSDs in both performance and value aspects. We have absolutely no reservations in recommending the SSD for use in a Thunderbolt 3 SSD enclosure.