"THIS is the answer, the one and only answer. Let's try to get Lenovo to make a patch for it:
Bios update made no difference for me with the same reduced speed cpu. I installed ThrottleStop8 and turned off BD PROCHOT and I now have a usable and quite fast machine.
01/26/2016 by kim
The bug seems to be only in Windows 10. Windows 8.1 worked (when the computer was new) without problems. Also Ubuntu works without any problems at all."
"I fixed the problem by correcting a mistaken setting under the Bootup tab of MSCONFIG, in Win10. I have a dual-core processor, and had set the Number of Processors to “2”. In fact, I have one processor and two cores. The correct setting is the have this set to “1”, then uncheck the CPU tick box, and reboot.
I stumble on that when I found that I was running on 1 core and 1 logical CPU, instead of 2 cores and 2 logical CPUs. When I fixed this (as above), it fixed my problem of the CPU being throttled to 800 MHz (instead of 2400 MHz) everytime I came out of hibernation under battery power."
