Raspberry Pi 5 Gets a MicroSD Express Hat

Summary

Will Whang’s RPI5-SDexpress-Hat is a small HAT+ for the Raspberry Pi 5, adding a microSD Express card slot for ultrafast storage, an eject button, and two Qwiic connectors, probably because there was still some spare space on the board…As a reminder, microSD Express cards can deliver SSD performance thanks to the use of of PCIe interface and NVMe commands. The standard was first introduced in 2019, and even earlier (2018) for full-size SD cards, but manufacturers have not exactly rushed to release compatible hardware. A major change this year is the launch of the Nintendo Switch 2 portable game console, one of the first mass market devices with a microSD Express slot, and this was partially why Will created the microSD Express HAT+ for the Raspberry Pi 5.RPI5-SDexpress-Hat board specifications: MCU – WCH CH32V003 RISC-V microcontroller for hotplugging and unmount Host interface – PCIe Gen3 x1 FFC connector Expansion – 2x Qwiic connectors Misc – Eject button, Power LEDs, Mounted LED Power Management 5V supply via 40-pin GPIO header (6-pin header used) 1.8V/3.3V fixed output LP5907 voltage PAM2306 step-down DC convertor for 1.8V voltage Dimensions – Small The good news is that it just works:Here are some storage benchmarks using PiBenchmarks.com with the Raspberry Pi 5 configured to use PCIe Gen3 x1: Category Test ResultHDParm Disk Read 631.68 MB/secHDParm Cached Disk Read 699.12 MB/secDD Disk Write 169 MB/sFIO 4k random read 48761 IOPS (195047 KB/s)FIO 4k random write 26290 IOPS (105160 KB/s)IOZone 4k read 22803 KB/sIOZone 4k write 137502 KB/sIOZone 4k random read 31366 KB/sIOZone 4k random write 178701 KB/s The read speed is indeed better than a typical microSD card (630MB/s+), but the sustained write speed is closer to a high-end traditional Class A1/A2 microSD card at under 200 MB/s. Random I/IOs are much better, too.You may wonder why a microcontroller is needed here. As one reader explained in our article about a microSD Express to M.2 NVMe SSD for the Nintendo ...