Delkin Devices Black CFexpress Type B Review

The Delkin Devices Black CFexpress Type B is a memory card for use in the latest cameras with a CFexpress type B card slot. While it can be used to record stills and 4K video, it has been developed with the demands of 8K video recording in mind and is specifically aimed at Nikon Z9 and Canon EOS R5 users.

Delkin Devices has recently extended the capacity range of the Black CFexpress Type B memory cards to 7, running from 64GB to 650GB. However, you need to check the read and write speeds of each capacity of the cards carefully to make sure you get the one you want as they vary thought the range as follows:

64GB Storage Capacity
Max Read Speed: 1685 MB/s
Min Write Speed: 1680 MB/s

75GB Storage Capacity
Max Read Speed: 1725 MB/s
Min Write Speed: 1240 MB/s

128GB Storage Capacity
Max Read Speed: 1760 MB/s
Min Write Speed: 1710 MB/s

150GB Storage Capacity
Max Read Speed: 1725 MB/s
Min Write Speed: 1530 MB/s

256GB Storage Capacity
Max Read Speed: 1645 MB/s
Min Write Speed: 1400 MB/s

325GB Storage Capacity
Max Read Speed: 1725 MB/s
Min Write Speed: 1530 MB/s

650GB Storage Capacity
Max Read Speed: 1725 MB/s
Min Write Speed: 1530 MB/s

I tested the 128GB card, which is the fastest of the Black CFexpress cards with a maximum read speed of 1760 MB/s and a minimum write speed of 1710 MB/s. These speeds put the Delkin Devices Black CFexpress Type B series ahead of the Delkin Devices Power CFexpress Type B range, but there’s a price premium to pay.

Like the Power CFexpress cards, the Black cards are covered by Delkin Devices’ lifetime warranty and 48-hour replacement guarantee. The latter sees any faulty registered card replaced within 48 hours (except at weekends). Delkin Devices states it will replace the card before the faulty one is received.

Although Delkin Devices says that its Black range of memory cards are the most robust cards that it makes, the Black CFexpress Type B cards looks and feel just the same as the Power CFexpress cards. Nevertheless the Black CF express cards is said to operate within a temperature range of 0-70°C, the Power card’s details just say ‘at extreme temperatures’, but it could be the same. Both card ranges are said to be shockproof, magnet-proof, X-ray-proof, anti-static and UV-guarded.

Like the Power CFexpress card, the Black CFexpress card has a metal covering on the front and back with the back cover extending around the edges to make it more robust.

There’s enough room to wiggle the Delkin Devices Black CFexpress Type B card from side-to-side (or up and down depending upon how you look at it) as it’s slid into the CFexpress card slot of a Nikon Z7 II, but there’s also enough grip to stop it from falling out.

As usual, the card meets with some resistance once it’s about two-thirds into the card slot and it’s just a case of pushing a little harder to get it to go all the way in. Once it’s in place, you can removed the CFexpress card by pushing it to release the catch so it pops out a little before you can extract it. A thin lip on the end of the card gives a little extra purchase to help with the removal.

Bench-testing the Delkin Devices Black CFexpress Type B with Blackmagic Design’s Disk Speed Test software found values of 925MB/s for the sustained read speed and 922MB/s for the sustained write speed. Both of these are lower than the claimed maximums, but that seems to be standard. The software also indicated that the card can be used to record 8K video at frame rates up to 144fps and 4K at up to 230fps. These figures are all near identical to the slightly more affordable Delkin Devices Power CFexpress Type B card.

In a real-world test of the Delkin Devices Black CFexpress Type B’s performance, it took just under 1 minute 50 seconds to transfer 200 uncompressed 14-bit raw files (taking up 16.3GB on the card) from the Nikon Z7 II to the desktop of an iMac. That’s actually almost 50 seconds longer than it took to move the same files from the Power card. To avoid the bottleneck within the computer, I transferred the same files from the card to a Samsung T7 Shield portable SSD and the transfer took about 30 seconds – a little less time than with the Power card.

Using the Black card as it’s intended in the 45,7MP Nikon Z7 II, I was able to shoot at the maximum continuous shooting rate of 10fps. And when shooting Fine-quality Jpegs, I was able to capture more than the 113-file burst depth claimed by Nikon with a blasts of around 130 images capture in 13 seconds. Switching to shoot 14-bit uncompressed raw files, however, dropped the burst depth to 44 files, a few short of the claimed 48-file maximum. This variation may well be explained by a difference in the file size in comparison to the files captured in Nikon’s tests.

Recording 4K 60P and 8K 30P video to the Delkin Devices Black CFexpress Type B proved unproblematic. The 128GB card has enough capacity to enable 6 minutes of 8K raw video to be recorded at 30p.

When shooting 4K 60P footage for the Nikon Z7 II’s maximum clip duration (29 minutes and 59 seconds), the Delkin Devices Black CFexpress Type B got quite warm when the camera was in an ambient temperature of around 20°C. Nevertheless, it was till possible to record for another 10 minutes before the camera overheated and shut down.

Although the Delkin Devices Black CFexpress Type B is a very good CFexpress Type B card, its hard to discern much benefit above the Delkin Devices Power CFexpress Type B card in normal use. While it may offer some advantages to regular 8K video-shooters, those who stick to 4K video and stills will find that the Power card does everything they need and costs a little less.

It’s great to see such a wide range of capacities of card available, but as 8K video eats through the capacity so quickly, some may wish for more than 650GB or need multiple cards. The lifetime warrantee and 48-hour replacement guarantee are reassuring.