Memory cards used to be simple. You bought the biggest one you could afford and called it done. In 2026, the card you pick determines whether your camera can record its highest video mode, whether your 30-frame-per-second burst clears in two seconds or sixty seconds, and whether you trust the card on a paid shoot. The labels (V30, V60, V90, UHS-II, CFexpress Type A, CFexpress Type B) describe real performance differences, and matching the wrong card to your camera leaves capability on the table or causes outright recording failures. This guide breaks down what each rating means and which card fits your kit.
The naming conventions explained
SD cards have three overlapping naming systems on the same card.
Speed class (the old system): Class 2, Class 4, Class 6, Class 10. These are obsolete for modern cameras. Class 10 means at least 10 MB/s sustained write speed.
UHS speed class: U1 (10 MB/s minimum) and U3 (30 MB/s minimum). Still printed on most cards.
Video speed class: V6, V10, V30, V60, V90. The number is the minimum sustained MB/s. This is the modern rating that matters for video record.
Bus interface: UHS-I (up to 104 MB/s peak), UHS-II (up to 312 MB/s peak), UHS-III (up to 624 MB/s peak, rarely seen). UHS-II cards have a second row of pins on the back. If your camera does not support UHS-II, a UHS-II card works at UHS-I speed.
CFexpress is a separate format with three sizes: Type A (used by Sony), Type B (used by Nikon, Canon, Panasonic, RED), and Type C (rarely seen in cameras). All three use the NVMe protocol over PCIe. Type A uses a single PCIe lane and tops out at about 1 GB/s. Type B uses two lanes and reaches 2 GB/s theoretical.
What V60 actually does
V60 guarantees 60 MB/s sustained write speed. That is enough for:
- 4K video at up to 400 Mbps (H.265 codec at 4K 60p)
- Most camera 4K modes from Sony, Canon, Nikon, Panasonic, and Fujifilm
- Single-shot raw photography on all current cameras
- Burst raw shooting that clears in 5 to 15 seconds depending on buffer depth
V60 cards from quality brands in 64 GB to 256 GB run 40 to 90 dollars. They are the right choice for most enthusiast 4K hybrid cameras. The ProGrade V60 in 256 GB at 80 dollars in 2026 is one of the best price-performance picks.
What V90 adds
V90 guarantees 90 MB/s sustained write speed and typically delivers 250 to 300 MB/s peak. It enables:
- 4K video at 600 Mbps and higher
- 6K raw video on cameras that record to SD (a small number, mostly Panasonic)
- 8K video on SD-slot cameras (rare in 2026, mostly Fujifilm GFX)
- Faster burst clearing on raw shooting (10 to 15 frames per second sustained for long sequences)
V90 cards run 80 to 200 dollars in 64 GB to 256 GB. The price gap over V60 is significant. The right buyers are videographers shooting high-bitrate 4K or anyone whose camera lists V90 as required in the manual.
The trap: many V90 cards label themselves V90 based on bursts and not sustained writes. Some 200 MB/s peak cards drop to 60 MB/s after 30 seconds of continuous recording. Look for independently tested sustained-write benchmarks from real reviewers, not the marketing peak number on the package.
CFexpress Type B specifics
CFexpress Type B is the standard for top-tier full-frame hybrid cameras in 2026 (Sony A1 II, Nikon Z9 and Z8, Canon EOS R5 Mark II and R1, Panasonic S1H II). The format enables:
- 8K raw video at up to 5.7 Gbps
- 6K raw at 4 Gbps with no thermal throttling on quality cards
- Burst raw stills at 30 frames per second with deep buffers that never fill in practice
- Sustained write speeds of 1.4 to 1.8 GB/s on the best cards
CFexpress Type B cards in 320 GB to 1 TB run 200 to 700 dollars. The high price reflects the underlying NVMe SSD technology, the thermal management required for sustained recording, and the small production volumes compared to SD.
Thermal management matters more on CFexpress than on SD because the cards run hotter under sustained loads. A card with poor thermal design throttles to 400 MB/s after 10 minutes of 8K recording and can cause dropped frames. Quality CFexpress cards include heat-spreading designs that maintain rated speeds for an entire battery’s worth of video.
CFexpress Type A specifics
Type A is Sony-only at the moment (A1, A9 III, FX3). The format is smaller than Type B and uses a single PCIe lane, capping theoretical bandwidth at about 1 GB/s. Real-world Type A cards deliver 700 to 800 MB/s sustained write speeds.
This is plenty for 4K 120p, 6K raw on some Sony bodies, and high-rate burst stills. Type A cards are expensive (200 to 400 dollars for 160 GB) because the format is Sony-exclusive and volumes are low. If you do not shoot a Sony body that requires Type A, ignore the format.
How to match a card to your camera
Step 1: check the manual. Modern camera manuals list the recommended card class for each shooting mode. Some video modes are flagged as requiring V90 or CFexpress specifically.
Step 2: buy from a reputable brand. ProGrade Digital, Sony, Delkin Black, Lexar Professional, Angelbird, Sandisk Extreme Pro. Avoid cards under 30 dollars from unknown sellers. Counterfeits are common and fail at the worst possible moment.
Step 3: buy at least two cards. Carrying a spare costs little and saves entire shoots. Pros routinely carry four to six cards split across the camera’s dual slots.
Step 4: format the card in the camera, not the computer. The camera writes the file system the way it expects to read it. Formatting on a laptop occasionally creates compatibility issues.
For more on the gear that uses these cards, read our companion guides on tripod heads and RAW vs JPEG workflow.
Frequently asked questions
What does the V rating on an SD card actually guarantee?+
The V rating is a minimum sustained write speed in megabytes per second. V30 guarantees 30 MB/s, V60 guarantees 60 MB/s, V90 guarantees 90 MB/s. The key word is sustained. Peak write speeds can be much higher, but the V rating is the floor the card must maintain across a long video record or a heavy burst clearing session. Your camera matches its video bitrate against this number.
Why is CFexpress Type B so much faster than even V90 SD?+
CFexpress Type B uses the NVMe protocol over a PCIe Gen 3 x2 interface, the same technology in modern SSDs. Theoretical bandwidth is 2 GB/s, and real-world sustained writes hit 1.4 to 1.8 GB/s on top cards. SD uses the much older UHS-II bus capped at 312 MB/s peak. CFexpress is roughly 5 to 10 times faster sustained, which matters for 8K video and high-rate raw burst stills.
Can I use a V90 card in a camera that supports CFexpress?+
Most cameras with a CFexpress Type B slot have a second SD slot that accepts V60 or V90 cards, but the SD slot has lower bandwidth. You can shoot stills to the SD card, but the highest bitrate video modes will be locked out. Always check the camera manual for the supported video formats per card type.
Do I need V90 if my camera only shoots 4K?+
Usually not. 4K at 100 to 200 Mbps fits well within V60 specifications (60 MB/s = 480 Mbps). V90 starts to matter for 4K at 400 Mbps or higher, 6K raw, and 8K modes. V60 is the practical sweet spot for most hybrid cameras shooting standard 4K H.265, and it costs 30 to 40 percent less than V90 at the same capacity.
Which brands of CFexpress card are reliable?+
ProGrade Digital, Sony Tough, Delkin Black, Lexar Professional Diamond, Angelbird AV Pro CFexpress, and Sandisk Extreme Pro have strong track records. Look for cards rated with thermal management (sustained write rates that do not drop after 5 to 10 minutes of continuous recording). Avoid no-name brands. A CFexpress card failure during a paid shoot costs far more than the savings on a generic card.
Priya Sharma
Priya Sharma writes for The Tested Hub.