The SD controller has been improved somewhat from the older Pi models, this article has some storage benchmarks: https://www.cnx-software.com/2019/06/24/raspber

The SD controller has been improved somewhat from the older Pi models, this article has some storage benchmarks: https://www.cnx-software.com/2019/06/24/raspberry-pi-4-benchmarks-mini-review/ https://www.cnx-software.com/2019/06/24/raspberry-pi-4-bench... Odroid has some eMMC performance numbers: https://magazine.odroid.com/article/orange-emmc-module-samsung-5-1-chipset-arrives/ https://magazine.odroid.com/article/orange-emmc-module-samsu... Though on either board the fastest storage you'll get will likely be a USB3->SATA bridge with an SSD.