FIRST - Format every card first with the SD Card Formatter Utility - this will fix 99% of issues. Afterwards use your OS Formatter utility to format the card as exFAT.
Most SD Card should work. If you are buying a new card go for one that is a name brand such as Western Digital, Samsung EVO, or Kingston Canvas (to name a few).
Buy from a trusted source with easy returns if the SD card is a fake or knock off. For example Identify fake SanDisk Extreme
Newer/faster SD cards will help when moving large images on or off the SD card, but wont change the performance while using it as a SCSI device. I personally use 16GB SD cards from the MicroCenter checkout line for ~$3/each.
There is some debate that that some SD cards do not support SPI - but that seems to be debunked.
Always remember to backup your data - SD Cards can fail too.
SanDisk and WCH STM32 clones
A few users have reported the WCH STM32 clones have issues with SanDisk SD cards. Not much more is known at this time but if you run into odd issues with a SanDisk please let us know and try a different SD card.
