Western Digital Previews 4 TB SD Card: World's Highest-Capacity
 

Western Digital's SanDisk Extreme Pro SDUC 4 TB SD card complies with the Secure Digital Ultra Capacity standard (SDUC, which enables up to 128TB). The card uses the Ultra High Speed-I (UHS-I) interface and is rated for speed Class 10, therefore supporting a minimum speed of 10 MB/s and a maximum data transfer rate of 104 MB/s when working in UHS104 (SDR104) mode (there is a catch about performance, but more on that later). WD's SD card is also rated to meet Video Speed Class V30, supporting a minimal sequential write speed of 30 MB/s, which is believed to be good enough for 8K video recording, above and beyond the 4K video market that Western Digital is primarily aiming the forthcoming card at.

https://www.anandtech.com/show/21349...ighestcapacity