Delkin Devices Black CFexpress Type B 4.0 card review

Delkin Devices has been pretty serious about memory cards for a few years now. In addition to a lifetime warranty, it offers a 48-hour replacement guarantee. This means that the company will replace any non-working (registered) card within 48 hours or less (not including weekends). You can also replace your card over the counter at any authorized Delkin reseller.

The Delkin Black card we're reviewing here is is built to the next-gen CFexpress 4.0 standard. This makes it around twice as fast as older CFexpress 2.0 cards, so it's ideal if you frequently shoot bursts of high-res Raw stills, or record 8K Raw video. I’m looking at the 325GB Black 4.0 card in this review.

As with some other cards, the maximum read and write speeds vary between the different capacity cards, but not by much. All are rated between 3530MB/s and 3700MB/s for peak read speed, and can manage a maximum write speed of 3130-3230MB/s.

Specifications

Max read speed: 3130-3230MB/s

Max write speed: 3530-3700MB/s

Available capacities: 325GB, 512GB, 650GB, 1TB, 1.3TB, 2TB

Build and handling

The rear metal casing of the Delkin Devices Black CFexpress Type B card extends around the edges to give a very robust feel. There’s also a metal plate on the front so that only a little of the plastic shell is exposed to the outside world.

The card slips easily into a camera card slot with just a little wriggle room before it snaps home fully. Depressing the card makes it pop-up ready for removal, but the fit is snug enough that it doesn’t drop out of the camera if you face the card slot downwards. You have to actively pull the card to remove it from the camera.

Performance

To put Delkin's speed claims to the test, we fired up CrystalDiskMark storage benchmarking software. This is capable of extracting the maximum possible performance from a memory card, but only if the supporting hardware is up to the job. So to ensure no testing bottlenecks, we used a fast Windows 11 laptop with USB4 connectivity. USB4 has a maximum 40Gbps bandwidth, equating to around 5000MB/s - more than enough to max out the theoretical 3530MB/s maximum read speed of our 325GB test card. Our CFexpress Type B card reader of choice is a USB4 model from ProGrade Digital.

Our testing returned a peak read speed of 2562MB/s and a maximum write rate of 1695MB/s. Not quite up there with Delkin's claims, but we've found this to be the case for most cards we've tested in this set-up. Crucially, it's more than enough speed for any shooting scenario, given that a camera like the Canon R5 Mark II 'only' needs a card capable of at least 325MB/s write speed when shooting 8K RAW footage.

Verdict

If you simply must have the fastest CFexpress Type B card on the market, then the Delkin Devices Black CFexpress Type B 4.0 card should be high on your shortlist. It's capable of incredible read and write speeds thanks to its CFexpress 4.0 interface, which are fast enough to exceed the stills or video requirements of any current consumer camera. Factor the generous number of available capacities, along with Delkin's stellar aftersales warranty support, and there's an awful lot to like here.

The only drawback is that you do pay extra for this premium performance and service. This is of course to be expected, but you should also ask yourself if you actually need this much speed? Sure, it's nice to stay futureproofed, but when CFexpress 2.0 cards with half the speed of this Delkin offering are already more than quick enough for the vast majority of shooting scenarios, for many the smart choice would be to go with a slower Type B card but with a higher capacity for a similar outlay.