dilbert said:
wow, not a single complaint yet of having loads of CF cards from the 5DIII that will be useless
Amazing
I've complained before, but with 4K video, the CFast is needed. The rated SD card speeds are just advertising, the speed is only as rated for a new card, once used, speed drops to a 30mb/sec and less. I probably not be buying a camera with CFast until all the bugs are worked out, 1DX II owners are finding out that the bugs are still not resolved.
If you do a lot of low level formats to get your speed back up, you shorten card life. Memory is usually rated for 500 to 3000 erase cycles before a hard failure, so you must use the low level format sparingly and put up with a slow card, or plan for failures and have spares or rotate a number of cards when using them for video. SD cards are a poor choice for video at best, which is why the CFast card is added.
Wikipedia:
Risks of reformatting[edit]
Reformatting an SD card with a different file system,
or even with the same one, may make the card slower, or shorten its lifespan. Some cards use wear leveling, in which frequently modified blocks are mapped to different portions of memory at different times, and some wear-leveling algorithms are designed for the access patterns typical of FAT12, FAT16 or FAT32.[96] In addition, the preformatted file system may use a cluster size that matches the erase region of the physical memory on the card; reformatting may change the cluster size and make writes less efficient.
SD/SDHC/SDXC memory cards have a "Protected Area" on the card for the SD standard's security function; a standard formatter may erase it, causing problems if security is used. The SD Association provides freely-downloadable SD Formatter software to overcome these problems for Windows and Mac OS X.[97] The SD Formatter does not format the "Protected Area", and the Association recommends the use of appropriate application software or SD-compatible device that provides SD security function to format the "Protected Area" in the memory card.