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
Now the question is single channel or dual channel RAM?
Spec sheet says 1x8 GB if max is 16GB then it's also make sense for a single channel slot. They don't put the usual 'up to xxx'. I'm a bit skeptic because of the usual history where vendor gimps AMD's laptop spec. This is without its reason because it isn't stated anywhere that this envy x360 supports active stylus because Intel's versions do support active stylus