Looking at Sandisk cards for a 5d markiii writing to both cards simultaneously (SD card to backup CF). Not shooting video, not shooting burst. Primarily weddings and portrait.
Could a CF Ultra 50mbps and SD Ultra 80mbps combo work??
You want much faster on the CF card. Each RAW from that camera is approx 25MB in size, some only writing 2 per second is far too slow.
My CF card is 160MB/s and it keeps up nicely. The slow down comes from the SD card, because the 5Diii cannot take advantage of the new SD card styles. I have a 95 MB/s in there, and I am pretty sure it doesn't fully take advantage of that. But it's nice to have the read speed when pulling the photos to a computer.
First one: A CF card is NOT the same as a CFast card. They are not at all compatible. The 5Diii cannot use a CFast card.
Second one: That is complete overkill for a 5Diii. The 5Diii does not have the extra pins needed to get that full UHS-II performance. See the pin layout of the back of the card: https://havecamerawilltravel.com/photographer/uhs-i-vs-uhs-ii-sd-microsd-cards You could at least read into your computer faster, but again, only if you buy a UHS-II reader
You want much faster on the CF card. Each RAW from that camera is approx 25MB in size, some only writing 2 per second is far too slow.
My CF card is 160MB/s and it keeps up nicely. The slow down comes from the SD card, because the 5Diii cannot take advantage of the new SD card styles. I have a 95 MB/s in there, and I am pretty sure it doesn't fully take advantage of that. But it's nice to have the read speed when pulling the photos to a computer.
