What are UHS interface and UHS Speed Class? Category : Specification / Capacity / Performance UHS (Ultra High Speed), the fastest performance category available today, defines bus-interface speeds of up to 312 Megabytes per second. It is exclusively designed for SDHC and SDXC memory cards, and compatible with SDHC and SDXC devices. Is the answer helpful? Related How come the files in my memory card are corrupted? Why does Transcend include the Proposition 65 warning? Why do I need to format the memory card before using it for the first time? Technical Support If the answer can't help you, you can contact the Tech Support Department Get Started