WHAT IS UHS SPEED CLASS 3?
Speed Class and UHS Speed Class symbols indicate minimum writing performance of your SD card. The Speed Class is denoted with a number inside a circle, and it’s the de-facto tell-tale number of the speed of your SD card. Typically, a Speed Class 10 card has a minimum serial data of 10MB/s. Lower speeds are available, such as Speed Class 6 rated at 4MB/s, although it’s outdated by today’s tech standards.
The new Ultra High Speed classification, known as UHS, is for UHScompatible devices. It’s shown on the SD card with a tiny, angular U-shaped symbol with a number inside that determines its maximum speed. UHS Speed Class 3 SD cards in our shootout has a minimum serial data at 30MB/s, and denotes the card meets requirements for 4K recording. The other speed, at UHS Speed Class 1, also has a minimum serial data of 10MB/s, but that doesn’t mean Speed Class 10 and UHS Speed Class 1 is interchangeable since they are different formats. Having the correct SD card with the correct device gives you the performance you need, and it’s particularly important if we are talking about 4K video recording.