I took some screenshots of what I see when the CPU starts being a renegade.
1. Picture "Performance" shows the CPU going crazy.
2. Picture "Processes" shows that there aren't any processes or apps running that would cause this issue such as a long video encoding or something like that.
3. Picture "svchost" shows that when I flip over to the Details tab PID 952 sticks out like a sore thumb in terms of RAM and also the CPU at 1% or 2%. Again it is interesting that the CPU is not 50% which is what the effect is on the Performance tab
4. Picture "fixed" shows the problem fixed after I End Task'd on PID 952.
This is a 3 week old install of Windows 8.0 and then upgraded to 8.1 on a Microsoft Surface Pro 8 with 128GB of hard disk. This was purcahsed about a month after they became available. The same issue was happening late last fall 2013 and I put up with it through the Holidays. Finally a few weeks ago I tried fixing it by restoring the factory settings and upgrading to 8.1.
I tried the Sleep workaround in the past and for me I don't ever remember it working. When the CPU went renegade it did just that until a reboot. My battery is dead in about an hour when this happens. After I kill the bad svchost.exe the Surface is normal. the fan turns off and the battery consumption is normal.
I wish Microsoft would fix this god damned problem.
