Question: how much 4k video can 512gb hold?
Answer: The 512GB card can hold about four hours of 4K Ultra HD video or about a full day's worth of 1080p video. Put in other terms, it takes about 11 hours to transfer 512GB over a 100BASE-TX Ethernet (100Mb/s) connection. SanDisk's Extreme PRO SD card also comes in 256GB and 128GB versions.