The mobile quad-core APU will purportedly run at a base 2 GHz clock rate with 6 MB of cache compared to the desktop 3.2 GHz Ryzen 5 1400 with 8 MB of cache.
https://www.notebookcheck.net/Low-power-AMD-Ryzen-5-2500U-CPU-may-be-coming-soon-to-the-HP-Envy-x360-series.258438.0.html