sony a7r iii memory card slots: Sony A7iii Memory Cards. Tested in Camera: The Best Sony A7R V Memory Cards - Alpha Shooters. Mirrorless Comparison: Nikon Z7 vs Sony A7RIII - Light And Matter.
While the Sony A7 III takes advantage of UHS-II memory cards, speeds will be bottlenecked to the slowest memory card in the camera depending on how you’re using
slot 1 and
slot 2 with the recording modes.
Sony has released a new version of their flagship full-frame mirrorless camera: the Sony a7R IV. After having been shooting with it quite a bit, here's my take.
Sony a7R III
Card Slot 2 is compatible with UHS-I memory cards. Sony SDXC UZ UHS-I memory cards with 90 MB/s Write Speed & 95 MB/s read Speed are an excellent choice.