Class 10 microSD card in MP3 players?

I have seen posts that suggest that class 10 microSD SDHC cards don’t work well with (SanDisk) MP3 players. These high speed cards are supposed to be optimized for high speed sequential access used for recording high quality video, thereby sacrificing random access speed, used predominantly in MP3 players. I have run benchmark tests with CrystalDiskMark on a Kingston class 4 SDHC card that works well and a Samsung class 10 card that occasionally gives problems (file not found message, or card error - please replug card message). Running the 4K random access speed test on both cards produced the following data: Class 4 card - Read: 2.768 MB/s, Write: 0.039 (!) MB/s Class 10 card - Read: 3.163 MB/s, Write: 0.522 MB/s So the class 10 card is faster on random access (too)! So I don’t understand why the latter card should cause problems. Therefore I would like an expert’s opinion about this. Also I would like to know if anyone can testify that class 10 DO work on MP3 players such as the SanDIsk CS. The reason that I am asking this is that nowadays the class 10 cards are very common and quite cheap and useful for other purposes. So why buying another class 2 or 4 card if you already have lots of class 10 cards? BTW, I could understand that an old MP3 player could not handle the newer and faster cards very well. But a device that was introduced in 2014 should handle the faster cards IMHO.


im using Transcend SDXC 64GB class 10 on my CS. no problem except the occasional freeze.

but i dont know if thats the cards fault. never used it without it. so…

also the stupid interface SanDisk implemented to seperate media from SD card and internal memory to 2 different menus.

I think that the understanding as to Class 10 speed issues with the Clips has been based on observation/experience, as opposed to engineering study.

Having said that, people have noted that Class 10 cards work fine with the Clips that run the separate Rockbox firmware. 

Just now sending back a 32 gb class 10, Doesn’t work well with the clip sport, had albums incomplete or non existent.

Spent hours trying to get it right with no luck.

Shouldn’t have to run another software, the one included should work with any card.

I have purchased a class 4 32 gig card, these are supposed to work well with this player.

Of course it would be nice if they did an update that would work well with at least most of the cards.

Yep, “should.”  :frowning: