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A Tale of two memory cards.... any insight welcomed

colporteur

What is the difference between a SD and a TF Memory card?

 

I purchased 10 TF memory cards from an online sight in January. My compatibility shields for the purchase were down due to the great price. Now with the cards not working in some application, I'm not sure it was such a great deal after all.

 

The first issue was the cards would not work with my SD card reader. The card reader was part of a swag bag I received from a vendor many years ago. The card reader was ideal because it had slots for a different types of cards and the physical size was ideal. TF cards didn't work in the reader. That same test proved true in both Linux and Windows operating systems. A quick switch to a card reader I purchased recently problem solved.

 

I soon discovered this issue with other card readers. I distributed five of the cards to different people for a project. Two of the five had to find an alternate card reader to use the card. I assumed old card readers verses new card reader was the issue.

 

I have been using the TF cards for a project using DFPlayers modules with no issues. This week I attempted to use the TF cards in a Raspberry Pi and they failed. The Pi will not boot. The boot sequence fails at a number of points. Sometimes the colour bar screen. sometime after the resize reboot and sometimes as boot messages are scrolling by. The card takes an O/S using Etcher without any issues. Both the Lite and the full version of Raspberry Pi OS provide the same results.

 

My research into SD verses TF cards has provided no insight. The acronym change appeared to be marketing advantages. Now I am not so sure self assured.

 

I'm curious what has been your experience with TF cards? I would appreciate if you could share any of your insight? I have whittled down the stock of TF cards to three. Based on my three month experience I will be leery of these cards in the future.

  • TF cards (trans flash) were re-named micro SD cards when the SD Association changed ownership.

    TF cards (or micro SD cards) did not follow SD standards when they were designed, the renaming was more about marketing than technology. That isn't bad, they are just separate development technologies.

    TF and microSD are the same and interchangeable, although different manufacturers have different reputations for quality.

    However it takes two to Tango - some devices are finicky about which micro SD card (or TF) they work with and some micro SD cards or TF cards are finicky about which devices they work with. Some devices work with any card. I am not sure it is just about quality or adhering to standards. Some high quality cards don't work with some finicky devices.

    I actually have more problems with SD cards than micro SD cards, but mostly I have few problems with either, and I buy the cheapest cards I can find. The cheap cards of today seem to work better than expensive cards did a few years ago.

  • in reply to dougw

    The memory card issue is new to me. I had finally used up my stock (large quantity purchased years ago ) of micro SD cards and was forced to go to the market and get more. The real world bite when you live in a bubble of things not changing.

     

    I have had both good and bad, expensive and cheap memory cards. If the cheap cards are bad, it doesn't hurt the pocket book as much. I tend to go with the cheap cards also and have had few complaints. This is the first time I have had a complete series of cards not work on Pi's.

     

    I would argue that TF and SD cards are not the same as implied. If SD cards are built to a standard and TF are not built to the standard then they are not the same.

     

    Is it possible TF cards are stock that failed the SD card standard but still work mostly? I seem to recall there was a story about two processors they were both identical except one failed a test and was downgraded so it could still be sold, just not like the first.

  • in reply to colporteur

    Wasn't it Intel that did this? They had some chips where the "extra" cores didn't function/pass verification so they re-branded them as lower core'd chips (a 16 core chip was now a "new" 12 core)

  • in reply to colporteur

    When I mentioned the standards were different, I meant the TF designers chose a different form factor with different features. I didn't mean they had an inconsistent or poor design.

    The thing that fails me the most is the SD card lock. There is a physical one that fails, but can be defeated and there is an electrical one that is petty tough to recover from if it decides to lock itself. There are recovery apps that can recover some cards but many manufacturers don't bother putting in a recovery mechanism.

    I have not had this problem with TF cards.