Lexar Professional DIAMOND CFexpress Type B Card Review

The Lexar Professional DIAMOND CFexpress Type-B cards feature PCIe Gen 3×2 and NVMe high-speed protocols. We previously reviewed Lexar’s first CFexpress Type-B card (simply named Lexar Professional at the time) a few years ago, which offered an impressive performance profile to suit most professional needs. Now Lexar has upped the game again.

The new Diamond series, is a fairly big step up as far as performance goes, making it currently one of the best options for power users in the film, photography and media industries working with 8K, 6K, and 4K video. The new card is also backward compatible with select XQD cameras, allowing for next-gen performance in these devices.

Lexar Professional DIAMOND CFexpress front

Best of class Performance Profile

The Lexar Professional DIAMOND CFexpress series offers the best potential transfer rates we’ve seen so far for a CFexpress Type-B card, quoting sequential reads and writes up to 1,900MB/s and 1,700MB/s, respectively, for both the 128GB and 256GB capacity points. In addition, minimum sustained writes are expected to stay at an impressive 1,600MB/s. As a result, Lexar indicates that professionals will experience consistent high performance when recording in any resolution, which will certainly speed up workflows.

In comparison, the SanDisk Extreme Pro CFexpress Type-B memory card is specced at speeds up to 1,700MB/s read and 1,400MB/s write (512GB capacity), while the Acer CFE100 is quoted at 1,600MB/s read and 1,200MB/s write for the same capacity point.

Lexar Professional Diamond Series Reliability

Like previous iterations, these Diamond cards are ruggedly built with durability in mind. With its shock and vibration-proof specifications, and resistance to extreme temperatures, professionals will be able to record video in pretty much any harsh environment. They are also backed by a generous lifetime limited warranty, so they will likely be around as long as your camera (as well as when you decide to upgrade your hardware).

Lexar Professional Diamond Series Pricing and Capacities

The Lexar Professional Diamond CFexpress Type-B cards go for roughly $200 (128GB) and $339 (256GB) when on sale. We will be looking at the 128GB model for this review.

Lexar Professional DIAMOND CFexpressSpecifications

Capacity	128GB, 256GB
Form Factor	CFexpress Type B
Interface	PCIe Gen3x2
Min sustained write speed	1,600MB/s
Sequential Performance	up to 1,900MB/s read up to 1,700MB/s write
Operating Temperature	-10° C ~ 70° C (14°F ~ 158°F)
Storage Temperature	-25° C ~ 85° C (-13°F ~ 185°F)
Dimension (LxWxH)	29.60 x 38.50 x 3.80 mm / 1.16” x 1.51” x 0.14”
Weight	7.65g / 0.016lbs
Warranty	Lifetime limited warranty

Lexar Professional DIAMOND CFexpress Design and Build

Like all Type-B CFexpress cards, the Lexar Diamond Professional cards measure slightly over an inch in width and one and a half inches in height, which is very compact for a storage device that can output around 1.5GB/s in reads.

Featuring a black and silver/white design, the front of the card displays the product name, form factor, capacity, potential speed, and company branding (a little diamond at the top-right corner). As professionals often work with many different memory cards, it is important to have this information easily readable, front and center.

Lexar Professional DIAMOND CFexpress back

The back of the card displays the usual product, manufacturing country, and serial numbers, as well as certifications.

Lexar Professional Diamond CFexpress Type-B Performance

For testing, we used the Lenovo ThinkStation P520 platform with the Lexar reader that was sent to us (not bundled with the card itself). This means it will take full advantage of the quoted speeds.

We will also be comparing the Lexar Diamond to the following CFexpress Type-B cards:

First up is the Blackmagic test, where is posted 1,549.5MB/s read and 1,500.7MB/s write. These were exceptional speeds, particularly the write performance. In comparison, the SanDisk Extreme Pro CFExpress posted 1,425MB/s read and 1,060MB/s write, while Lexar Professional and Acer cards were able to reach 825MB/s read and 487MB/s write and 1,276MB/s read and 1,004MB/s write, respectively (all of which used the BlackJet CFexpress reader).

Moving onto the first IOMeter benchmark, we tested the new Lexar Diamond card in both a single-thread workload and 4-thread workload. Here, it posted 1,256MB/s write and 1,385.4MB/s read in 2MB sequential transfer speeds, while 2MB random performance hit 1,130MB/s write and 1,204.1MB/s read.

Here’s how it compared to the other CFexpress Type-B cards. As you can see, in all tests, the Lexar Diamond was the clear winner by a significant margin:

IOMeter (1-Thread)
Test	Lexar Diamond Professional	SanDisk Extreme Pro	Acer CFE100	Lexar Professional
2MB sequential write	1,256MB/s	965.7MB/s	280.05MB/s	433.03MB/s
2MB sequential read	1,385.4MB/s	1,086MB/s	1,165.88MB/s	700.08MB/s
2MB random write	1,130MB/s	397.4MB/s	145.87MB/s	428.30MB/s
2MB random read	1,204.1MB/s	1,036.7MB/s	754.88MB/s	696.07MB/s
4K random write	14,897 IOPS	3,145 IOPS	294.18 IOPS	22,198 IOPS
4K random read	4,328 IOPS	10,768 IOPS	7,170 IOPS	8,906 IOPS

The last test is the 4-thread IOMeter benchmark, which puts a heavy workload on the cards. In the 2MB sequential workload, the Lexar Diamond saw 1,767.5MB/s read and 1,599.9MB/s write, while random loads recorded 1,552.4MB/s read and 759.4MB/s write.

Again, here is a rundown of how it fared against the competition:

IOMeter (4-Thread)
Test	Lexar Diamond Professional	SanDisk Extreme Pro	Acer CFE100	Lexar Professional
2MB sequential write	1,599.9MB/s	1,270.89MB/s	318.23MB/s	524.63MB/s
2MB sequential read	1,767.5MB/s	1,223.73MB/s	1,422.38MB/s	944.76MB/s
2MB random write	759.4MB/s	362.4MB/s	152.18MB/s	510.40MB/s
2MB random read	1,552.4MB/s	1,213.84MB/s	1,064.86MB/s	948.23MB/s
4K random write	54,167 IOPS	8,289 IOPS	1,149 IOPS	53,347 IOPS
4K random read	14,913 IOPS	40,390 IOPS	25,613 IOPS	23,513 IOPS

Conclusion

While traditional SD and microSD cards are meant for more casual applications, the CFexpress form factor offers a serious boost in transfer speeds. After putting it through our tests, the Lexar Professional Diamond Series is clearly the best of them, making the high-end series a no-brainer for serious media professionals.

That said, they are only available in two capacities, 128GB and 256GB, so those who have larger storage needs might shy away from making a purchase despite its impressive performance. Hopefully, larger models will be released in the future.

Lexar Professional DIAMOND CFexpress with reader

While we didn’t quite reach its quoted potential speeds of 1.9GB/s read and 1.7GB/s write, it still significantly outperformed its competition. As for the specifics, it was able to hit top speeds of 1,549.5MB/s read and 1,500.7MB/s write in our Blackmagic test, while reaching 1,385.4MB/s read and 1,256MB/s write in IOMeter (1-Thread). We also tested its random 2MB performance, which showed 1,204.1MB/s read and 1,130MB/s write. The next best performing card was the SanDisk Extreme Pro, which saw 1,086MB/s read and 965.7MB/s during the 2MB sequential workload and the SanDisk scored 1,036.7MB/s read and 397.4MB/s write in 2MB random workloads.

We also put it through a 4-thread test (which pushes the cards a bit further). Here, the Lexar Diamond saw 1,767.5MB/s read and 1,599.9MB/s write, while random loads recorded 1,552.4MB/s read and 759.4MB/s write. Again, the 512GB SanDisk Extreme Pro was 2^nd among the tested cards, which was able to reach 1,223.73MB/s read and 1,270.89MB/s write for sequential 2MB speeds, while random performance saw 1,213.84MB/s read and 362.4MB/s write.

While the Lexar Diamond Professional is by far the best-performing CFexpress Type-B card on the market, you will be paying a premium price for them. The 128GB and 512GB models go for around $200 and $339, respectively. This is quite higher than the SanDisk Extreme Pro, which is currently on sale for $140 and $270 at most online retailers like Amazon and B&H. But if you need the best possible performance, the extra cost is definitely worth it.

The combination of its reliability, lifetime warranty, and impressive performance makes this a great addition to a niche market (i.e., compatible cameras cost anywhere from $2K to a whopping $50K+). But if you’re in need of the ultimate performer and have the right camera, the Lexar Professional DIAMOND CFexpress certainly fits the bill.

The Lexar Professional CFexpress Type B Card DIAMOND Series Product Page

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