Confused about memory card classification?

Posted on July 29, 2016 by Sean MacDonald

Memory card classification is confusing for most people, especially when there are multiple categories and classifications. This can be a little overwhelming even for people in the industry like camera store employees. In comes ProMaster...

To help educate camera store employees, the great people over at ProMaster have put together this little helpful guide to share with sales staff. They send out a weekly newsletter that is full of helpful stuff, and I got special permission to share this as I thought it was great information not just for sales staff, but also customers alike. Take a look at it if you are a little confused on memory cards. Enjoy!


What do UHS-1 and UHS-2 Mean
and How Does it Apply to Rugged and Velocity Memory?
The markings on memory cards can be confusing for customers, especially since the
introduction of UHS-2 cards to the market. Here is a quick primer of what these markings mean.

A. The “number inside the ‘U’ marking is the UHS Speed Class. A UHS Speed Class 1 indicates a 10 MB/s minimum write speed, and a UHS Speed Class 3 indicates a 30MB/s minimum write speed. (It is worth noting UHS-I, UHS-II and speed class ratings are used on SD and microSD only. And UDMA only relates to CF.

B. The “Roman numeral” – either a I or a II, is the UHS Rating. UHS-I cards support up to a 104MB/s read speed, and a UHS-II support up to a 312 MB/s read speed. Your customer will need a UHS-II compatible device to take full advantage of the speed, but they are backwards compatible and will work in any device, regardless of the rating. The Nikon D500, Fuji X-T1, Fuji X-PRO 2, Olympus E-M5 II, and Olympus Pen-F are all UHS-II compatible …

So how does this apply to ProMaster Rugged and Velocity?
ProMaster Rugged cards are UHS-I (shown with Roman numeral I) speed class three.

Rugged SD cards: 
  • Read speed 99MB/s (660X),
  • Write speed 80MB/s,
  • UHS-I speed class 3

Rugged micro SD cards:

  • Read speed 99MB/s (660X)
  • Write speed 60MB/s
  • U3 UHS-1 speed class 3. U3

Rugged Compact Flash cards:

  • Read speed 160MB/s (1060X)
  • Write speed 80MB/s
  • UDMA 7

ProMaster Velocity cards are faster, so they carry the UHS-2 (shown with Roman numeral II) speed class three designation. UHS -2 has a second set of contacts.

Velocity’s write speed is 25% faster than AWXC and Rugged cards at a blistering 100MB/s! They download files at an incredible 285MB/s! That is 1900x transfer speed.

A note about ‘X’ speeds and actual speed - ‘X’ speeds are always derived from the read speed of a card, not the write speed. So be careful of cards with high ‘X’ ratings that seem too cheap. They may read fast, which is great for big downloads to the computer; but they may not perform well in-camera if the write speed is low.

Make sure you have Rugged cards if you want extra insurance against impact and the elements … and make sure you have Velocity cards if you need blazing speed.

If you have any further questions or need a new memory card, feel free to stop in!

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