Faded memories - testing SDHC (and other) cards

While flying my new DJI Flip after a recent POTA activation, a warning appeared on the screen of my remote controller:

"SD card speed low. Normal use may be affected. Replace SD card."

This was from an SDHC card I'd used many times previously with no problems - a SanDisk Extreme Pro.

I reformatted the card but continued to get the warning. So I replaced it and the drone recorded video with no problems and no warnings.

Like just about everyone else, I've accumulated a decent collection of SD and SDHC cards over the years. Even the tinySA can make use of one, as can an Icom 705 and many other radios.

So I decided to test them, using a free program called SpeedOut.

 

The results were pretty much as expected except for the card that had given me the warnings. I have two identical SanDisk Extreme Pro cards and they both have very different write speeds. I ran the test on each card 4 times and the results varied only by 2MB/s or so.

After measuring all my cards, I reformatted each of them and named them based on their Read/Write speed by typing that 4-digit number into the 'Volume Label' field.

I am surprised at the slow SanDisk card. It still reads the normal (labeled) capacity, it's just slowed down in its old age... 

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