Looking for good information on Memory Cards

[Lodovico]

I've done some good searching on here, but I can't find anything recent regarding memory card selection. Would just like to read about some of the options and consideration, and what impact it can have as far as speed, burst mode, better cards to use for video, that type of stuff.

Anyone have good articles to link to that discuss memory cards?

 

[Derrel]

Rob Galbraith has an EXCELLENT CF-,SD-, and XQD Card Database section on his site, www.robgalbraith.com

Here is the direct link to that section Rob Galbraith DPI: CF/SD/XQD Performance Database

 

[Lodovico]

Rob Galbraith has an EXCELLENT CF-,SD-, and XQD Card Database section on his site, www.robgalbraith.com

Here is the direct link to that section Rob Galbraith DPI: CF/SD/XQD Performance Database

Great! Thanks.

 

[TCampbell]

Two things:

Marketing types will post "claims" on the product claiming certain speeds. But it turns it's generally possible to "read" data from a card much much faster than you can "write" data to a card (and this has to do with how the two different operations work on flash memory.) So the marketing folks will make claims that the card transfers "20 Megabytes per second" -- but then NOT bother to tell you if that was "burst" speed vs. "continuous" speed and whether it was "read" speed vs "write" speed.

What you REALLY want to know is: What's the CONTINUOUS WRITE speed? That's the what the camera is doing when you are recording video... streaming data to the card continuously. The marketing folks generally shy away from that question because it's usually the lowest number so it doesn't look all that impressive.

Enter the SD Card Association

They've constructed standardized tests to determine the speed of the card and, based on what the card is able to consistently pass, the card gets to use a seal/icon which is an indicator of this benchmark speed. If they pass a card as a "Class 6" card then it means the card is capable of performing transfers of AT LEAST 6 megabytes (or faster) in ALL OPERATIONS and can do so CONTINUOUSLY. That means you can be sure the card can at least read at 6 megabytes per second and can also write at 6 megabytes per second. It may go faster... but it goes "at least" this fast. If a card can "read" data in burst at some 30 megabytes per second... but then can only "write" data continuously at 6.3 megabytes per second, then that card is a "Class 6" card.

The association has a mark for Class 2, 4, 6, 10 (notice I skipped 8 - for some reason there was no 8) and then the next speed up is called "UHS 1".

For video, the camera MUST have a card which is Class 6 or Class 10 (10 is better). A class 2 or 4 card wont be able to keep up with video and this will usually cause the camera to stop recording as soon as the camera buffer fills and the card can't keep up.

The new UHS 1 spec is special. This is a totally new class (Ultra High Speed) and these cards can be 100 MBPS to several hundred MBPS, but it does require a different SD card bus in the camera and typically only the newest cameras have it. UHS 1 cards are backward compatible (you can stick a UHS 1 card into a camera that doesn't support the high-speed UHS 1 bus and it will still work... it just wont be the ultra high speed.)

See: https://www.sdcard.org/consumers/speed/speed_class/

I've seen LOTS of stories of people who claim they put a card in their camera and it's giving them problems. Sometimes you get what you pay for. I find the Lexar brand and Sandisk brand to be highly reliable.

 

[Lodovico]

Two things:

Marketing types will post "claims" on the product claiming certain speeds. But it turns it's generally possible to "read" data from a card much much faster than you can "write" data to a card (and this has to do with how the two different operations work on flash memory.) So the marketing folks will make claims that the card transfers "20 Megabytes per second" -- but then NOT bother to tell you if that was "burst" speed vs. "continuous" speed and whether it was "read" speed vs "write" speed.

What you REALLY want to know is: What's the CONTINUOUS WRITE speed? That's the what the camera is doing when you are recording video... streaming data to the card continuously. The marketing folks generally shy away from that question because it's usually the lowest number so it doesn't look all that impressive.

Enter the SD Card Association

They've constructed standardized tests to determine the speed of the card and, based on what the card is able to consistently pass, the card gets to use a seal/icon which is an indicator of this benchmark speed. If they pass a card as a "Class 6" card then it means the card is capable of performing transfers of AT LEAST 6 megabytes (or faster) in ALL OPERATIONS and can do so CONTINUOUSLY. That means you can be sure the card can at least read at 6 megabytes per second and can also write at 6 megabytes per second. It may go faster... but it goes "at least" this fast. If a card can "read" data in burst at some 30 megabytes per second... but then can only "write" data continuously at 6.3 megabytes per second, then that card is a "Class 6" card.

The association has a mark for Class 2, 4, 6, 10 (notice I skipped 8 - for some reason there was no 8) and then the next speed up is called "UHS 1".

For video, the camera MUST have a card which is Class 6 or Class 10 (10 is better). A class 2 or 4 card wont be able to keep up with video and this will usually cause the camera to stop recording as soon as the camera buffer fills and the card can't keep up.

The new UHS 1 spec is special. This is a totally new class (Ultra High Speed) and these cards can be 100 MBPS to several hundred MBPS, but it does require a different SD card bus in the camera and typically only the newest cameras have it. UHS 1 cards are backward compatible (you can stick a UHS 1 card into a camera that doesn't support the high-speed UHS 1 bus and it will still work... it just wont be the ultra high speed.)

See: https://www.sdcard.org/consumers/speed/speed_class/

I've seen LOTS of stories of people who claim they put a card in their camera and it's giving them problems. Sometimes you get what you pay for. I find the Lexar brand and Sandisk brand to be highly reliable.

Wow. Lots of great information. Thanks!

 

[Tinderbox (UK)]

Buy Samsung Memory Card`s they are fast and as tough as nails, i have had other makes fall apart, never again will i buy another brand, i buy a lot from Amazon and had no problems.

John.

 

[pixmedic]

I use SanDisk 16GB class 10 SDHC UHS-1 45MB/S cards.
been very happy with them. I dont do enough continuous "burst" shooting or video to need the 95mb/s or higher cards, and the SanDisk cards have held up and performed extremely well (except for the ones that got eaten by our puppy...those arent working so well now)
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