CFexpress Type A vs Type B Cards Explained for Your Camera
Choosing between these memory cards isn't about picking the better format, but rather matching the specific hardware requirements of your camera body. Manufacturers lock users into one form factor because the physical slot dimensions and internal bus architecture differ significantly. While Type B is the industry standard for high-end cinema cameras, Type A exists primarily to fit smaller, compact mirrorless bodies that lack the space for a larger card.
Quick facts
| Feature | Type A | Type B |
|---|---|---|
| PCIe Lanes | 1 | 2 |
| Physical Size | 20 x 28 mm | 38.5 x 29.8 mm |
| Common Use | Compact bodies | Cinema/Pro bodies |
What are the physical dimensions and pin configurations of Type A versus Type B cards?
Type A cards utilize a single-lane PCIe interface with a compact 20 x 28 mm footprint, while Type B cards double the lane count and occupy a larger 38.5 x 29.8 mm space. These dimensions dictate the internal pin layout, with Type B offering a wider interface to support its increased data traffic.
| Metric | Type A | Type B |
|---|---|---|
| PCIe Lanes | 1 | 2 |
| Interface Width | 20 mm | 38.5 mm |
| Pin Count | 34 | 48 |
| Max Bus Speed | 1 GB/s | 2 GB/s |
Use these physical specs to make sure your card reader matches the card format.
How do the maximum theoretical read and write speeds compare between these two form factors?
Type B cards easily outperform Type A in theoretical speed, often reaching read speeds of up to 1,700 MB/s compared to the 800 MB/s typical of high-end Type A media. This bandwidth gap exists because Type B uses dual PCIe lanes to move significantly more data every second.
Which camera manufacturers currently support Type A cards, and which favor Type B?
Sony remains the primary driver of the Type A format, while most other professional camera manufacturers have standardized on the larger, more versatile Type B design.
- Sony cameras like the A1 and A7S III exclusively utilize Type A slots to maintain small body dimensions.
- Nikon professional bodies such as the Z8 and Z9 rely on Type B for their high-speed buffer clearing.
- Canon mirrorless flagships like the R3 and R5 series incorporate Type B slots to handle massive 8K raw video files.
- Fujifilm utilizes Type B in its flagship medium-format GFX series to manage the immense data generated by high-resolution sensors.
Is there a performance bottleneck when using Type A cards in high-resolution video recording?
Yes, Type A cards often create a bottleneck during high-bitrate video recording because their single-lane architecture cannot match the sustained write speeds of Type B. While Type A handles 4K well, it may struggle with the massive data demands of 8K raw recording at high frame rates.
Are CFexpress cards backward compatible with older XQD or SD card slots?
CFexpress cards are not backward compatible with XQD or SD slots, though some cameras with XQD slots can accept Type B cards after a firmware update. A lot of people assume that because the physical shape of an XQD card is nearly identical to a Type B card, they are interchangeable, but they use different communication protocols. Always check if your specific camera model has received the manufacturer's firmware patch to enable CFexpress support, as hardware compatibility alone does not guarantee that the camera will recognize the newer storage media.
How does the cost per gigabyte compare between Type A and Type B storage media?
Type B cards are generally much cheaper per gigabyte than Type A, as the larger form factor allows for more flash memory chips to be packed into the casing. You will find that high-capacity Type A cards carry a significant price premium due to the engineering required to shrink high-speed controllers.
| Capacity | Type A Price | Type B Price |
|---|---|---|
| 160 GB | ~$350 | ~$180 |
| 320 GB | ~$650 | ~$300 |
| 640 GB | ~$1,200 | ~$550 |
Compare these prices against your storage needs to avoid overspending on high-capacity Type A media.
What specific photography and videography workflows benefit most from the higher capacity and speed of Type B cards?
Professional workflows involving 8K raw video capture or high-speed sports photography benefit most from Type B cards. When shooting 30 frames per second on a flagship mirrorless camera, the buffer fills instantly; the dual-lane speed of Type B makes sure the camera clears that data to the card without locking up the shutter. This is essential for wildlife photographers who need to capture long, continuous bursts without missing a moment.
Cinema production houses also rely on Type B for long-form recording in high-bitrate codecs like ProRes RAW. While Type A is sufficient for standard 4K, it lacks the sustained write endurance required for these heavy-duty tasks. An exception exists for hybrid shooters who prioritize a smaller camera footprint; they might choose a Type A body for travel, accepting the slower offload times as a trade-off for portability.
How can a user verify their camera's specific compatibility requirements before purchasing a new memory card?
Consulting the manufacturer's official technical documentation or the specific camera's menu settings remains the most reliable way to confirm which media your device requires.
- Manuals provide the definitive list of supported card types and recommended minimum write speeds for your specific model.
- Websites maintained by camera brands often feature a compatibility chart that lists tested and verified memory cards for video recording.
- Icons printed on the camera body near the card door serve as a quick visual reference for the required format.
- Firmware update notes might reveal if your camera has gained support for newer, faster card specifications since its initial release date.
What people often get wrong
- Assuming cards are interchangeable. You cannot force a Type B card into a Type A slot, and a Type A card won't fit a Type B slot. Check your camera manual before buying.
- Overestimating speed needs. You don't always need the fastest card available; check your camera's maximum write speed to avoid paying for performance your camera cannot utilize.
- Ignoring heat management. High-speed cards generate significant heat during sustained recording. Make sure your card is rated for the specific bitrate and codec your camera uses.
Match your card to your camera
Verify your camera model's specifications on the manufacturer's website to identify the required card type. If your camera supports both, prioritize Type B for better value and speed, or stick to Type A if you value the compact size of your current mirrorless setup.