Equipment Guide GUIDE-156 Document Checked
Camera Memory Card Buying Guide: The Truth About UHS-I / UHS-II / CFexpress Type A/B and V60/V90 Speed Ratings
Expose the marketing trap of '300MB/s read speed' on packaging boxes, analyze the physical mechanisms of write speed and video sustained write rating (V30/V60/V90), and establish the optimal storage solutions for different models and bit rates.
CATEGORY Equipment Guide
Topic storage and power
PUBLICATION Publishable
1. Memory card core performance nominal and pit prevention cheat sheet
| Memory card form specifications | Physical gold finger ranking | Nominal true maximum sustained writing speed | Video speed grade certification | Typical applicable shooting scenarios | Pitfall warning |
|---|---|---|---|---|---|
| Ordinary SD UHS-I | Single row gold finger (8 Pin) | 60 - 90 MB/s | V30 (guaranteed continuous writing ≥ 30MB/s) | 24 million pixel daily static single photo, 4K 30p normal bit rate video | Continuous shooting of 10 pictures will freeze and clear the cache and wait for a few seconds |
| High-speed SD UHS-II | Dual-row gold fingers (17 Pin) | 150 - 260 MB/s | V60 / V90 (guaranteed continuous writing ≥ 60/90MB/s) | 30-60 million pixels high-speed continuous shooting, 4K 60p/120p All-Intra extremely high bit rate | Must use UHS-II support card reader, ordinary card readers will slow down to 80MB/s |
| CFexpress Type A | Sony's exclusive micro card (small size) | 700 - 800 MB/s | VPG200 / VPG400 | Sony A1 / A7S3 / A7R5 shoot 8K and 4K 120p 4:2:2 10-bit full specifications | Extremely expensive, only used by some high-end Sony mirrorless cameras |
| CFexpress Type B | Similar size to XQD (mainstream standard) | 1400 - 1700 MB/s | VPG400 | Nikon Z8/Z9, Canon R5, Fuji X-H2S shoots 8K RAW video and 30fps continuous shooting | The writing speed is very fast and the cache is cleared instantly, but the heat is extremely high and requires a metal card reader to dissipate heat |
2. Why is it said that "just looking at the big numbers on the packaging box will cost you a lot"?
- Read Speed (Read Speed) scam: The manufacturer prints "300MB/s" in large fonts on the front of the packaging box. In fact, this is often the read speed (the speed of copying photos into a computer) under ideal conditions in the laboratory.
- The only thing to consider when shooting with a camera is the write speed (Write Speed): When shooting continuous shooting and high-bitrate videos, the speed at which the camera writes data to the card is the only bottleneck between life and death! If a card reads 300MB/s, but continuously writes only 50MB/s, the camera will fall into a long "busy while writing" freeze state after two seconds of continuous shooting.
- Look for the "V" logo and the "VPG" logo:
- Common specifications for shooting 4K 60p: Must look for V30 or V60;
- Shooting 4K All-Intra high bitrate or 4K 120p: V60 or V90 memory card must be used;
- Shooting 8K RAW: CFexpress card required.
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Sources:: src_cipa_battery_testing_standard, src_focal_press_manual_of_photography Report Inaccuracy / Propose Edit
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