Two Qualcomm Reference Devices (QRD) have been spotted online. They're powered by the company's upcoming Snapdragon 8 Elite SoC and come with UFS 4.0 storage and LPDDR5X RAM. https://www.notebookcheck.net/Snapdragon-8-Elite-2-engineering-samples-spotted-online-with-blazing-fast-clock-speeds.1043659.0.html
This is likely just an indication of RAM clock speeds—4.8 GHz (4800 MHz) and 5.3 GHz (5333 MHz)—which are standard speeds for LPDDR5X memory.