Delkin Devices Power CFexpress Type B Review

Delkin Device’s Power CFexpress Type B card is the more affordable of the two CFexpress Type B card lines that Delkin Device offers. With data transfer speeds of up to 1730/1540 MB/s read/write, the Power cards are recommended for shooting stills at high speeds or recording 4K or 6K video. Meanwhile the Delkin Devices Black CFexpress Type B cards are recommended for 8K video and most demanding cameras like the Nikon Z9.

Delkin Devices offers the Power CFexpress Type B cards in five capacities, 128GB, 256GB, 512GB, 1TB and 2TB. Unlike the company’s Black CFexpress Type B cards, the Power CFexpress cards have the same maximum data transfer speeds at every capacity, read: 1730 MB/s and write: 1540 MB/s. This is enabled by their use of a 3rd generation PCI Express interface and support of NVM Express.

Consequently, the Delkin Devices Power CFexpress Type B is ideal for recording 4K or 6K raw video at high frame rates and bitrates, but if you want to shoot 8K video then you should opt for a Delkin Devices Black CFexpress Type B card. Similarly, the Black card is required to get the full potential of the Nikon Z9 and Canon C300 Mark III.

A nice bonus of the Delkin Devices CFexpress cards is that you get a 48-hour replacement guarantee if you register the card after purchase. This gives you the peace of mind that the company will replace the card within 48 hours (apart from at weekends) if it stops working. You can send the card to Delkin Devices or take it to a Delkin Devices retailer for replacement.

Looking very much like all other CFexpress cards, the Delkin Devices Power CFexpress Type B is chunkier and more solid-feeling than the more common SD-type media.

The front and back of the card have a metal casing with the rear casing wrapping around the side of the card to give a nice robust feel as only a little of the plastic body is exposed.

According to Delkin Devices, the Power CFexpress Type B cards are also ‘shockproof, magnet proof, X-ray proof, anti-static, UV-guarded and resistant to extreme temperatures’ – but I think that’s a claim that can be made by most if not all CFexpress card manufacturers.

Testing the Delkin Devices Power CFexpress Type B in the Nikon Z7 II, I found the card slips smoothly into the camera’s card slot (it also has an SD-type card slot). There’s a little side-to-side movement available if you wiggle the card but not so much that the card feels loose or ill-fitting.

The card slides in until about two-thirds of its depth is in the camera before some resistance is felt and then it’s just a case of pushing a little harder to get the CFexpress cards home fully. Even if it’s turned off, the Nikon Z7 II flashes a green light on its rear to let you know that the card has registered in position.

To remove the card from the camera, simply press it in a little and it pops out so that roughly a third of it is showing and it can be pulled out completely. A thin lip on the end of the card gives a little extra purchase.

For my first test of the Delkin Devices Power CFexpress Type B card, I set the 45.7Mp Nikon Z7 II to ISO 100 and manual focusing mode to avoid any focus delay or hunting and switched to Continuous High (extended) shooting. I was then able to shoot 42 14-bit uncompressed raw files in a single burst lasting around 4 seconds. This matches the 10fps maximum shooting rate but Nikon claims a burst depth of up to 48 files. The difference may be explained by variation in the files size in comparison to Nikon’s images.

Changing to shoot fine-quality Jpegs, the Z7 II was able to capture 111 files in approximately 11 seconds, coming close to the 113 files claimed by Nikon.

Crucially, the images captured in the two files types are immediately available for review and you’re not left waiting with the camera locked-up. However, you need to wait around 14 seconds before you can shoot another long burst of images.

Next, I fired up Blackmagic Design’s Disk Speed Test software to measure the sustained read and write speeds obtained with the Delkin Devices Power CFexpress Type B connected to my iMac via a Lexar Professional CFexpress Type B USB 3.2 Gen 2×2 card reader. This showed values of 924 MB/s for the read speed and 922 MB/s for the write speed. As usual, these figures are lower than the sustained read/write speeds claimed by Delkin Devices, but Disk Speed Test also indicates that the card can cope with recording 4K video at up to 230fps and 8K video at 144fps.

In a more real world test, I again connected the Delkin Devices Power CFexpress Type B card to my iMac via the Lexar CFexpress Type B card reader, but this time I transferred 200 14-bit uncompressed raw files taking up 16.3GB of space on the card from it to the computer’s desktop. This transfer took under 1 minute 3 seconds.

Transferring the same 200 images from the card to a Samsung T7 Shield (a portable SSD storage unit) connected to the computer via the USB-C cable supplied with the SSD reduced the transfer time to 31 seconds. This illustrates the bottleneck that’s present in some computers, but that is removed by using the USB-C/Thunderbolt connectivity.

Naturally, I have also used the Delkin Device Power CFexpress Type B card in the Nikon Z7 II for normal use and it has matched my expectations, enabling me to shoot bursts of images at the 10fps maximum frame rate. It also performs satisfactorily when recording 4K video at 60p, taking the 29 minute 59 second clip maximum in its stride. Both the card and the camera get warm when recording long clips like that, but neither gets excessively hot. Nevertheless, in an ambient temperature of around 20°C, the camera shut down after a total of 40 minutes of 4K 60p video was recorded in two clips recorded back-to-back, because it was too hot.

If you’re not planning to shoot 8K video on a regular basis, the Delkin Devices Power CFexpress Type B makes a great choice of CFexpress card. It also comes backed with both a lifetime warranty and the 48-hour replacement guarantee.

As I’ve seen with every CFexpress card I’ve tested, it doesn’t match the claimed data transfer rates in bench testing with Blackmagic Design’s Disk Speed Test, but it performs extremely well in real world testing, enabling cameras like the 45.7Mp Nikon Z7 II to perform to their potential.