Through this test, I used the Nextorage NX-B1PRO CFexpress Type B Memory Card in the Canon EOS R5 C and the performance met expectations, easily handling the high-resolution demands. The card didn’t cause any errors or issues through recording, maintaining a consistent read and write speed that aligned with the manufacturer’s transfer claims. However, I obviously couldn’t check that it was hitting the upper end of the write speed in the camera.
On that, it is worth noting that it’s important to remember that the card’s speed performance might be limited by the device it’s paired with. When testing in camera the Blackmagic Disk Speed test, the performance of the Thunderbolt 4 port on the MacBook Pro was found to be the limiting factor, not the card itself. Consequently, the actual transfer speeds achieved during this test were lower than the card’s potential with a write speed of 1267MB/s and a read speed of 1445MB/s.
Heat dissipation, a crucial aspect in high-speed data transfers, is well-managed in the NX-B1PRO due to its pSLC technology, ensuring the card stays within safe operating temperatures even during extended periods of high-resolution recording.
A really nice touch from Nextorage is that they supply data recovery software for Mac and PC that can be downloaded from their website. It’s powerful and can be a lifesaver in recovering accidentally deleted files, although the recovery success rate may decrease after formatting the card in-camera.

The Nextorage NX-B1PRO is an extremely well-priced solution, especially compared to similar CFexpress Type B cards in the market, like Lexar. However, the smaller capacity of the 165GB version may prove to limit if you’re shooting video but couples well with the Canon EOS R5 for stills and occasional video use.