Sandisk Pro G40 Thunderbolt SSD Review

The Sandisk Pro G40 portable SSD is marketed towards creative professionals and stands out thanks to its Thunderbolt & USB 4.0 compatibility, promising multiple gigabytes per second of transfer rates. But it also is (mostly) backwards compatible to slower USB devices that lack Thunderbolt technology.

I put it through its paces in my most recent review.

Because it’s a “professional” product this drive comes it at a higher price point, about $174 for the 1TB version (compensated affiliate link).

The drive’s build quality is impressive, featuring a solid, rubberized metal design with a grippy bottom, common in other SanDisk drives. It is IP68 weatherproof, making it resistant to splashes, though users should avoid exposing it to harsh weather when plugged in.

It comes with a short Thunderbolt 3 cable USB-C cable which will also work on computers not equipped with USB-C. Other cables, like USB-C to USB-A cables will work as well but those will need to be purchased separately.

Performance tests on a Thunderbolt-equipped Windows computer showed it achieving over 2.4 gigabytes per second in read and write speeds, maintaining this without thermal drop-offs or cache issues. For optimal performance, it’s crucial to connect to the correct port, identified by the Thunderbolt or USB 4.0 icon, as using a standard USB port significantly reduces speeds.

The CrystalDiskMark benchmark further highlighted its strengths in sequential and random reads and writes, suggesting potential for PC gaming. Comparisons with other USB-C-based drives such as the SanDisk Extreme Pro and Samsung T9 showed the Pro G40’s superior performance in Thunderbolt mode. Speeds were comparable to competitors when not connected to the Thunderbolt, however.

The SanDisk Pro G40 SSD contains an off-the-shelf WD Black SN850 NVMe (compensated affiliate link) drive inside its enclosure.

Notably, the Pro G40 does not work with iPhones, which limits its utility despite its potential for high bitrate, lossless video formats. Attempts to use it with other phones also failed, possibly due to power draw issues, making it suitable primarily for computers.

For Windows users, achieving full performance requires enabling write caching in the drive’s settings. I outlined those steps at the 6:12 mark in the video review. This extra step is unnecessary for Mac users, where the drive works at full speed out of the box.

While the Pro G40 is compatible with game consoles, its high performance can’t be utilized, making it an impractical choice for that purpose. However, for PC gaming and professional creative work, it offers excellent performance akin to internal drives. Despite its limitations with mobile devices, the Pro G40 is a compelling option for those needing a fast, reliable external drive.