Best CFExpress Type-B Memory Cards – Real Benchmarks with Thunderbolt

The latest CFexpress Type-B memory cards are some of the fastest and most robust types of media you can use for your cameras today. But just how fast are they?

This guide will look at the different performance metrics of the various brands of memory cards.

Best CFexpress Memory Cards – Benchmarks

CFexpress Type B cards can be very fast with USB 3.2 2×2 which runs at 20Gbps, or Thunderbolt 3. Mac Computers, even the new ones M2Pro in 2023 do not support USB 3.2 2×2 even the new computers that USB4 are only backward compatible with USB 3.2 10Gbps, but they do use Thunderbolt 3 or 4 at 20Gbps. PCs can be found with motherboards that support USB 3.2 2×2.

All USB-C CFexpress readers you buy for Mac will only run at 10Gbps, even though some advertise 20Gbps. For 20Gbps speeds you can buy Thunderbolt readers, there are only a few on the market.

Testing Method

For these benchmarks there are two column sets, one set is taken with USB 3.2 2×1 speeds on a Macbook Pro with an Angelbird or Prograde reader (whichever worked best), and the Second Row was tested with an OWC Thunderbolt 3 reader.

What you should pay attention to is the Heat column as this shows the card’s performance after thermal throttling or it’s sustained speed.

The software used was AJA System Test Lite. Resolution: 5120×2700 5k Red / Test File Size: 4GB / Codec Type 16bit RGBA, Single File, DMA Mode: Dual Engines.

USB and Thunderbolt speeds are taken by recording with a 4GB Test File Size to simulate burst shooting, since few cameras have a buffer larger than 4GB, and the heat column is taken with 64GB file sizes to simulate video recording.

Click the plus button to see rated read and write speeds as well as the rated sustained speeds – not all brands of cards advertise their rated sustained speeds, although they should all write it on their cards as Prograde now does since that’s the only spec that matters for videography.

Few notes. Some cards work better in different memory card readers. If a card was not performing well in one reader I would swap the reader to see if I could get better results. You probably should just buy the same reader as the cards you buy unless you buy an OWC reader or one of their docs that has the CFexpress slot. A few cards seemed to have some compatibility issues with the Thunderbolt OWC reader and I could not get proper speeds with them, these include the Lexar 512GB and 128GB cards.

Top 3 Best CFExpress Cards – The All-Around Best Brands For 2023

After benchmarking all the different cards in all the different cameras there have been a few brands that have stood as being better than others.

For Nikon shooters, my top picks of brands would be Lexar or Delkin, also the Prograde cards can be a nice option. 

Nikon shooters should stay away from OWC and Angel Bird cards since they are a little too thick for the Nikon card slots and can get stuck.

Sandisk has a new Pro Cine card that I’ve yet to test, but this could put Sandisk back on the recommendation list.

The Sony Tough card still thermal throttles too aggressively for it to be a top pick.

Why some cards were so much slower?

There are now a lot of options for CFexpress cards and some are intentionally designed slower to make them cheaper. These are great for photographers that are only concerned with casual photographers or low-bitrate video recording. Not everyone needs the fastest CFexpress card, especially if you’re on something like a Nikon Z6 II that only records video at 150Mbps.

Some cards have very aggressive thermal throttling profiles which were more apparent with the large file size tests vs smaller file size tests.

I performed these tests using the AJA System Test using 4GB file sizes. The reason I chose 4GB is that this is about the buffer we see in some of the best cameras like the Sony A1 or A9. The Nikon Z9, also a great camera, only looks to have about a 2GB buffer. This makes sense, it’s using faster CFexpress Type-B cards instead of Type-A cards.

If I chose a larger size than 4GB in these benchmarks, it could cause the card to engage the thermal throttling more aggressively, and it wouldn’t show the potential capabilities of a camera like the Sony A1 which would be limited to a 4GB buffer. However, cameras with a smaller buffer like a Nikon Z9, could show better performance with some of those slower cards because they would not be used as often under the throttled conditions. While these slower cards do show tested results significantly slower than their rated performance, their peak bursts were actually showing closer to those rated numbers.

In other words, if you have a Nikon Z6 or Z7 with only a 2GB buffer, you may not notice the difference between a super-fast card or a slower card, especially since those early CFexpress cameras were still only using one PCIe 3.0 lane anyway. The new cameras like the Z9 are looking like they are taking advantage of the dual lanes of the CFExpress Type B cards.

Best CFexpress Type-B Memory Card Reader

Although I can’t see the full speeds of USB 3.2 gen 2 2×2 with a 2018 Macbook Pro, the Lexar CFexpress Type-B reader is clearly performing better than the other brands. I have two other Prograde readers a Pergear reader, a Sandisk reader, and an Angelbird reader. If you’re on a USB 3.1 or M1 Mac, it won’t matter which reader you use since the speeds will be throttled by the bus throughput.

I recommend these two readers unless you use Angelbird cards, then go with the Angelbird reader so you can update the firmware. 

See the Best CFexpress Type B Memory Card Readers for more information.

USB-C CFexpress Type-B Readers

These are the readers I have and use. They all work great. Some can be slightly faster than others depending on what card is used, but for the most part they are all very close in speed.

Lexar CFxB + USB-C Reader – Amazon / B&H

If you can’t take full advantage of USB 3.2 setup or need UHS-II, the Prograde UHS-II + Cfexpress reader is only slightly slower, most would never notice the difference.

Prograde UHS-II + CFxB Reader – Amazon / B&H

The Prograde readers all now support the faster Sandisk interface so a lot of those UHS-I cards now run properly at the 170MB/s read speeds.

Angelbird CFxB Reader – Amazon / B&H

You’ll need an Angelbird Reader to upgrade the firmware in Angelbird Cards.

ThunderBolt Readers

OWC Thunderbolt 3 Reader – Amazon / B&H

OWC also has a few Thunderbolt 3 docs with a built-in CFexpress reader.

ProGrade CFxB + XQD Thunderbolt 3 Reader – B&H

Fastest CFexpress Type B Cards Bottom Line

Now that the CFxB space has matured, there are a lot of great options for cards at various prices. You don’t always need the fastest CFexpress card and can save a lot of money buying a card that only has the specs you need.

Keep an eye on thermal throttling with the higher-end cameras and cards as that’s going to be a better benchmark to look at compared to RAW speed if shooting video is the primary use of the camera.