For the sheer variety of high-performing, feature-rich devices, the SD Association introduced higher speed bus interface (I/F) and its minimum writing speed specifications for SDHC memory cards and SDXC memory cards.
*Maximum speed differs from the bus I/F speed. It varies depending upon the card performance. The average speed that a device writes to an SD memory card may vary depending upon the device and the operation it is performing. The speed may also depend on how other data is stored on the SD memory card.
Normal and high-speed cards can also be used with UHS-I host devices, but the high performance enabled by a UHS-I host device can only be achieved with a UHS-I memory card.
UHS-II Pin Layout
A new pin layout was introduced to support the UHS-II bus interface. The new second-row pins on the full-size SD memory card and microSD memory card are used for the UHS-II signals. The first-row pins are used for the normal speed, high speed and UHS-I bus interface signals to provide interoperability with existing non-UHS-II host devices.
UHS-II Specification & Test Guideline
1. SD standard overview
2. SD specification overview
3. UHS-II test guideline
With the respect to the information contained within this page (“Information”), no express or implied patent, copyright, trademark, or other proprietary rights are licensed, granted, or otherwise transferred by this disclosure hereunder and no liability is assumed by the SDA for any damages, or any infringements or other violation of the rights of the SDA or any other parties, which may result from their use or any portion thereof. The information is provided by the SDA wholly on an “AS IS” basis and no warranties of any kind are given with respect to the Information. THE SDA HEREBY DISCLAIMS ALL WARRANTIES, WHETHER EXPRESS, IMPLIED, OR STATUTORY, INCLUDING WITHOUT LIMITATION ANY IMPLIED WARRANTIES OF MERCHANTABILITY, OF FITNESS FOR A PARTICULAR PURPOSE, NON-INFRINGEMENT, QUALITY, ACCURACY, TIMELINESS, AND COMPLETENESS.