The CFexpress memory card format is becoming increasingly popular, but it can be confusing for people who are used to SD cards, CFast or CompactFlash. In this guide, we will take a look at the differences between the Type A and Type B CFexpress cards and examine the pros and cons of cameras using these formats. We’ll also take a look at the various symbols found on CFexpress cards so that you have a complete understanding of which cards are suitable for your camera.
Table of Contents
- CFexpress Type A Vs Type B
- CFexpress Card Naming, Numbers, Speeds and Symbols
- What Is CF Express Version 2.0?
- CFexpress Type C
- XQD Vs CFexpress Type B
- CFast Vs CFexpress
- Frequently Asked Questions
CFexpress Type A Vs Type B
Should CFexpress Type Affect Your Choice of Camera?
CFexpress Card Naming, Numbers, Speeds and Symbols
Cfexpress card capacity will be marked on the card and is either in gigabytes (GB) or terabytes (TB). There are 1000GB in 1TB. The current largest capacity of CFexpress card is 4TB, but lower capacities such as 128GB, 256GB, and 512GB are far more common.
CFexpress Card Speed
Most CFexpress cards will indicate their speed on the card, written as XXX MB/s and corresponding to a maximum speed in megabytes per second (MB/S). It’s important to understand that these are maximum speeds, available only in short bursts. Sustained read and write speeds will always be slower. There are three possible ways in which maximum burst rates might be shown:
- If a single number is displayed, it will correspond to the maximum read speed, which is usually higher than the write speed.
- If two numbers are displayed, one will be indicated by a W for maximum write speed, and one will be indicated by an R for maximum read speed. Sometimes these are explicitly written ad Read and Write.
- If a card’s maximum read and write speed is the same, this will be indicated by R/W before or after the speed in MB/s.
Sustained Minimum Write Speed – VPG Standards
Maximum read and write speeds can give us a reasonable picture of one card’s speed compared to another, but sometimes the important specification is the minimum sustained write speed. This is particularly important when recording video or shooting long bursts of high megapixel photos in a high burst rate with a camera such as the Nikon Z9 or the Sony a1.
Thankfully, there is a standard for testing this. The VPG standard indicates the minimum sustained write speed of a CFexpress card and is shown on the card by a number within a movie clapper board symbol. Testing is performed independently by the CompactFlash Association. VPG400 and VPG200 are common standards, although I expect to see faster standards unveiled in a few years’ time as CFexpress card technology develops.
4K, 8K, 12K
Some CFexpress cards carry a symbol that is meant to show consumers that they can record specific video resolutions such as 4K or 8K. This is not standardized CFexpress symbology, and it should be ignored entirely. Whether a card is capable of recording a specific resolution of video is entirely dependent on the bitrate of the codec that is being used by the camera.
All CFexpress cards can write some form of video in any resolution. Even CFexpress Type A cards can write 12K video if the bitrate is low enough. Some brands place these symbols on a CFexpress card to try to fool consumers into thinking that their card is somehow better than a card that does not carry a 4K or 8K symbol. The VPG standard is the crucial symbol when it comes to video recording. Your camera will very likely tell you what the minimum VPG standard is for the various recording formats it’s capable of creating.
IP65, 66, 67
We can again refer to the above image of the Exascend CFexpress card for a reference to this symbol. In this instance, the IP67 symbol they have included on the card is governed by an international standard so it does provide some useful information. The first number indicates resistance to dust, while the second number indicated resistance to water ingress.
A number 6 in the first position means that a product is entirely resistant to dust. A number 5 in the second position would indicate a card protected from condensation and light moisture spray. A number 6 in the second position would show a memory card protected from a moderate amount of water spray, such as rain. A number 7 in the second position indicates a card that can withstand heavy water spray or submersion in up to 1m of water for 30 minutes. An 8 in the second position is completely waterproof for continuous immersion.
In some cases where extensive waterproofing clearly makes the product entirely protected from dust, the first digit might be left as an X. Then you will see the rating written as IPX6, IPX7 or IPX8. With IP67 on it, our example card is resistant to dust and waterproof in up to 1m of water for 30 minutes.
One thing to note about these durability standards is that some CFexpress card manufacturers do not put them on the card itself. This symbol may only be visible on the card’s packaging or listed in specifications on the manufacturer’s website.
ProGrade Digital “R” Symbol
ProGrade Digital CFexpress Type B cards feature an R-shaped symbol. This is not a standardized symbol for CFexpress cards. Instead, it means that the card can be used with ProGrade Digital’s proprietary Refresh Pro software that claims to sanitize your cards and return them to a “factory fresh” state. I do not have experience with the software, so I cannot pass comment on its effectiveness.
What Is CFexpress Version 2.0?
One of the more confusing aspects of CFxpress cards is the version number that several card manufacturers use. The original CFexpress 1.0 specifications only included what we now know as CFexpress Type B. The 1.0 specification used two lanes of PCIe 3.0 and the NVMe 1.2 stack. In 2019, CFexpress 2.0 was launched. This new standard included specifications for two new form factors, Type A and Type C, and moving everything to the NVMe 1.3 stack for a marginal performance increase.
If all of this sounds confusing, you are not alone, and it’s for this reason that most CFexpress card brands don’t even bother to mention the Cfexpress version on their products. All you need to know is that if you have a CFexpress Type A card, it must be CFexpress 2.0 because Type A did not exist under the CFexpress 1.0 specifications.
As for Type B cards, moving from the NVMe 1.2 stack to 1.3 in CFexpress 2.0 might cause a slight performance increase, but the theoretical maximum is still 2000MB/s because both CFexpress 1.0 and 2.0 Type B cards use two lanes of PCIe 3.0. Instead of judging CFexpress cards by whether they are version 1.0 or 2.0, it is far better to look at their maximum read and write speeds and their sustained write speeds. Please do not get hung up on whether they are Version 1.0 or 2.0. All new CFexpress cards launched in 2022 and beyond are 2.0 cards.
CFexpress Type C
- Type A: 20mm (width) x 28mm (length) x 2.8mm (thickness)
- Type B: 38.5mm (width) x 29.6mm (length) x 3.8mm (thickness)
- Type C: 54mm (width) x 74mm (length) x 4.8mm (thickness)
We’ve looked in detail at the Type A and Type B CFexpress cards, but there is also a third standard called Type C. You might not have heard about this type of memory card because currently, there are no cameras on the market that support this format. As you can see from the diagram above, CFexpress Type C will theoretically offer maximum speeds that are twice that of Type B.
If we ever see Type C cards make it onto the market, I do not doubt that they will first be used by high-end cinema cameras looking to shoot 8k or 12K video at high-speed frame rates far above 60fps. Current cinema cameras like the RED Raptor can shoot 8k RAW video at up to 120fps onto CFexpress Type B cards, so it’s going to take a further leap in camera technology to create a future need for Type C cards. Look to companies like ARRI, Red, Canon, Blackmagic and Sony for these kinds of cameras in the future. However, I guess that they are still a few years away.
XQD Vs CFexpress Type B
XQD is a memory card format developed by Nikon, Sony and Sandisk and launched before CFexpress. While XQD was initially touted as a replacement for CompactFlash (CF) cards and even had the backing of the CompactFlash Association, the format failed to gain widespread adoption. Likely due to its lacklustre maximum speed of 500MB/s.
The XQD card format was an abject failure. While Nikon did put XQD slots in their cameras, Sony never bothered, and Nikon was forced to upgrade camera firmware so that their XQD slot-equipped cameras could use the much faster CFexpress Type B cards.
Here, then, is the clever thing. When the CFexpress card standard was being designed, they chose to make CFexpress Type B cards physically identical to XQD cards. This includes their dimensions and their pin layout. The decision allowed Nikon to save some face by creating firmware that allowed their XQD cameras to work with much faster and cheaper CFexpress cards. At the same time, other manufacturers who had been investigating the use of XQD could make a straight switch CFexpress Type B instead.
A small handful of XQD cards were produced by Nikon, Sony, Sandisk and Delkin, but they all have significantly slower speeds and smaller capacities than CFexpress Type B cards. All cameras that use XQD cards can now also use CFexpress cards, so there is no good reason to buy an XQD card anymore. You should buy a CFexpress Type B card instead.
CFast Vs CFexpress
Frequently Asked Questions
Are CFexpress cards more durable than SD Cards?
If you consider the manufacturer’s specifications, it would appear that SD cards are similar in durability to CFexpress cards. Most SD and CFexpress cards have similar ranges for operating temperature; many of them are also drop-resistant to a similar degree. However, in this instance, I do not believe that specifications tell the full story.
I have been using SD cards for over fifteen years, and every single SD card failure I have experienced has been the same. The plastic ribs found on most SD cards are fragile. They can sometimes break the entire card casing or cause connectivity issues if they fail. This design is the SD card’s biggest weakness. Only Sony, with their TOUGH brand of SD cards, has solved this problem by producing a ribless SD card, as seen in the image above.
Cfexpress cards, on the other hand, do not have these fragile plastic ribs on them. You will not find them on CFexpress Type A or Type B cards. So, while the actual memory chips found inside SD cards and CFexpress cards should be similarly durable, I firmly believe that CFexpress cards will prove more durable in the long term. If your camera uses both SD and CFexpress cards and you’re trying to choose between buying one or the other, consider this.
Can you use an SD card reader with a CFexpress card?
No. An SD card reader will not with CFexpress Type A or Type B memory cards. You will need to purchase a dedicated CFexpress reader. We have tested many CFexpress readers and detailed them in a buying guide. If you use a combination of SD and CFexpress cards in your cameras, our guide contains some excellent card readers with slots for both SD and CFexpress cards.
Can you use an XQD card reader with a CFexpress card?
You cannot use an XQD card reader with a CFexpress Type A card, but you might be able to use it with a CFexpress Type B card. XQD is a now-defunct type of memory card that was used in a small number of cameras. XQD cards themselves are physically identical to CFexpress Type B cards, meaning a Type B card will fit into an XQD card reader. However, the card reader needs to have been specifically designed for use with both XQD and CFexpress Type B. The only way to confirm this is to check the manufacturer’s specifications. The Sony MRW-G1 and ProGrade Thunderbolt Reader are popular XQD card readers that work with CFexpress Type B cards.
Why are CFexpress cards so expensive?
Compared to SD cards, CFexpress cards are a much newer technology. Many more cameras use SD cards than CFexpress cards. Greater SD card production contributes to economies of scale. Prominent manufacturers of SD cards have also had twenty years to refine the efficiency of their production line and raw material acquisition. As more and more cameras use CFexpress cards, we will see prices decline. Although CFexpress prices seem expensive now, they were considerably more expensive when they first launched. Even in the last couple of years, CFexpress prices have dropped by around 25%.
It’s also worth considering that SD cards are available in much smaller capacities than CFexpress cards. The cheapest SD card or Micro SD card on the shelf might only be 16GB in size and cost a few dollars. On the other hand, the smallest available capacity of CFexpress cards is around 64GB. CFexpress cards are more expensive, but the dollar to capacity ratio might not be as bad as it seems.
How long do CFexpress cards last?
CFexpress card manufacturers do not state estimated lifespans for their products. However, there is no reason to expect the cards to last any less time than a good SD card. I have SD cards that have been in use for ten years! If you buy a CFexpress card from a reputable brand, you should expect it to last for many years.