It may not read that if the 1.4GHz is a boost speed. On Intel CPUs the turbo speed would be shown only as 1001MHz for example. The additional 1 indicates turbo is active.
I'm not sure how the APU 'boost' might be shown. It may not. It's probably detailed in the APU2 thread though:
https://forum.netgate.com/topic/95148/pc-engines-apu2-experiences