Table of Contents
ToggleSpeed Class of SD Cards
Class | Speed | Our opinion |
Class 4 | 4MB/s | Too slow for most modern cameras. Skip it. |
Class 6 | 6MB/s | A little bit better but unless you take 3 pictures a year, skip it. |
Class 10 | 10MB/s | Good enough for most cameras with 20+ megapixels and Full HD video. |
U1 (UHS) | 10MB/s | Good enough for most cameras with 20+ megapixels and Full HD video |
U3 (UHS) | 30MB/s | Perfect for fast burst cameras, Full HD at 60fps and 4K video. This is what you want for A7 III |

- Lexar Professional 300MB/s UHS-II U3
- SanDisk Extreme Pro 300MB/s UHS-II U3
- SanDisk Extreme Pro 95MB/s UHS-I U3
Lexar Professional 300MB/s UHS-II U3

SanDisk Extreme Pro 300MB/s UHS-II U3

SanDisk Extreme Pro 95MB/s UHS-I U3

Card | Size | Speed |
Lexar Professional 300MB/s U3 | 64GB | Writing files: ~240MB/s. Reading files: ~270MB/s |
Sandisk Extreme Pro 300MB/s U3 | 64GB | Writing files: ~230MBs. Reading files: ~260MB/s |
Sandisk Extreme Pro 95MB/s U3 | 32GB | Writing files: ~90MBs. Reading files: ~95MB/s |
What Brands are the Best?
Your photographs and videos are stored on a memory card, so you should definitely not try to save any money here by buying from unknown, cheap brands. While you save a few bucks, you probably won’t even get the advertised speeds, and are at a bigger risk of losing your shots. We see too many beginners choosing the cheap route here, but until you transfer your shots to a computer/online, this is where they’re stored at. You want the memory card to be the most reliable piece of your equipment! Stick to Sandisk, Lexar, Transcend, Kingston, Sony and Toshiba. There may be a few other good brands out there, but the ones we mentioned are already more than enough and offer great prices.Related Articles
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