Reviews |Lexar Professional Type B Card Diamond series

Lexar Professional Type B Card Diamond series Review

Lexar Professional Type B Card Diamond series

Price when reviewed



Our Verdict

The Lexar Professional Type B Card Diamond series is designed for the latest cameras that can shoot at 4, 6 and 8K. The card offers transfer speeds that are levelled well beyond the needs of most stills photographers but is an ideal solution for hybrid shooters and videographers.

The card features Transfer speeds up to 1900MB/s; this speed of data transfer is well beyond the present abilities of our test equipment, with most card readers only connecting through USB Type-C. The test showed that the transfer speeds were at the top end of what was possible with our equipment, and rigorously tested over 12 hours, the card remained steady without causing errors.

Used in a Canon EOS R5, the card kept up with the demands required by the camera to capture the higher resolution video data.


  • Incredibly fast
  • Large capacity
  • Durable


  • Expensive

What is the Lexar Professional Type B Card Diamond series?

The Lexar Professional Type B Card Diamond series is the fastest CFExpress card on the market. With read speeds of up to 1900MB/s and write speeds of 1700MB/s, few other cards or cameras at present come close to the performance.

Not only is the card fast, but it has been fully tested to provide that performance over a full-day shooting. What will also appeal to many videographers is that the card is backwards compatible with XQD cameras, although not all.

Lexar has rigorously tested the card for use in professional systems, so it is marked with the VPG 400 video class specification that guarantees a minimum write speed of 400MB/s.


  • Read speed: 1900MB/s
  • Write speed: 1700MB/s
  • Capacity : 128GB, 256GB
  • Form factor: CFExpress Type-B
  • Backward compatibility: Some XQD devices


Starting the test, the CFExpress card was formatted inside the Canon EOS R5 and then tested using the Blackmagic disk Speed. The card instantly proved its worth regarding the read and write speeds within our test equipment, although we instantly hit an issue. The Lexar Professional Type B Card Diamond series offers transfer speeds of 1900MB/s, while the USB Type-C card reader only connects through USB Type-C. The issue with this is that this maxes out at transfer speeds of 1250MB/s in ideal situations, and once you consider a slowdown due to the cable and reader, the card’s performance should max out the system.

Lexar Professional Type B Card Diamond series

Sure enough, the results came back as follows:

Write: 893.5MB/s
Read: 906.7MB/s

While this allows some headroom in the test, it shows the speed and quality of the card even through this connection type limited the actual transfer rates that we could test. In the real-world test, it took just 4 minutes and 38seconds to copy the 140GB (Around 5000 files) from the card to the hard drive of a MacPro M1 Max.

In-camera the card was formatted and used all day to film using 4, 6 and 8K video at 25fps. The card and camera worked without a hitch, although filming pushed the internal and external battery capacity of the camera more than the storage medium.

Final Thoughts

Through the test, there is no doubt that the Lexar Professional Type B Card Diamond series impresses. From the computer data transfer test to the real-world tests in the Canon EOS R5, the card pushed the transfer speeds of the equipment it used.

Lexar Professional Type B Card Diamond series

Lexar does state that this is a professional-level card and comes with a price tag to match. This means that while any level of user can take advantage of a card that will enable their camera to perform to its full potential when it comes to speed, few cameras at present can fully use the performance.

If you own one of the latest cameras, such as the Canon EOS R5 or R5 C, this card is worth a look. It has the capacity, speed and, beyond everything else, the reliability to perform with consistent performance through a day’s shoot.


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