I have found thousands of users all asking the same exact questions, but there doesn’t seem to be any definitive answers from SanDisk as to what the difference between their part numbers are.
There is also another post here: http://forums.sandisk.com/t5/Mobile-memory-professional-cards/Questions-about-UHS-1/m-p/278646/highlight/false
I have similar questions. It is very unclear what the differences are between various Sandisk MicroSD cards.
The 64GB MicroSD Ultra has several variants which all show “up to 30MB/s”:
SDSDQUA-064G-U46A - 64GB microSDXC Class 10 / UHS-1
SDSDQUA-064G-A11A - 64GB microSDXC Class 10 / UHS-1
SDSDQUI-064G-A11A - 64GB microSDXC Class 10 / UHS-1
SDSDQY-064G-U46A - 64GB microSDXC Class 6
Does anyone know what the difference between the “SDSDQUA-064G” and “SDSDQUI-064G” part numbers means?
Does anyone know what the difference between the “-U46A” and “-A11A” part numbers mean?
I have read in various forums that:
1 - The class 6 is better for random read-write than the class 10. Is this true?
2 - They are all the same card, just the labels have changed. Is this true?
3 - They are all the same card, but the formating is slightly different out of the box… but when reformatted, they all perform the same…True?
Any definitive answers here?