Thread.Sleep used to be tied to the system clock which clocked in at a interval at roughly 16 ms, so anything below 16ms would yield 16ms sleep. The behaviour seems to have changed some way down the line line.
What has changed? Is Thread.Sleep no longer tied to the system clock but to the high res timer? Or has the default system clock frequency increased in Windows 10?
edit: It seems people are intersted in knowing why I use Thread.Sleep, its actually out of the scope of the question, the question is why the behavior have changed. But anyway, I noticed the change in my open source project freepie https://andersmalmgren.github.io/FreePIE/
Its a input/output emulator which is controlled by the end user using Iron python. That runs in the background. It has no natural interrupts. So I need to marshal the scripting thread so it does not starve an entire core.
Thanks to Hans Passant comment which I first missed I found the problem. It turns out Nvidias driver suit is the problem maker.
Platform Timer Resolution:Outstanding Timer Request A program or service has requested a timer resolution smaller than the platform maximum timer resolution. Requested Period 10000 Requesting Process ID 13396 Requesting Process Path \Device\HarddiskVolume2\Program Files\NVIDIA Corporation\NVIDIA GeForce Experience\NVIDIA Share.exe
This is so idiotic on so many levels. In the long run this is even bad for the environment since any computer with nvidia will use more power.
edit: Hans Comment, relevant part:
Too many programs want to mess with it, on top of the list is a free product of a company that sells a mobile operating system. Run powercfg /energy from an elevated command prompt to find the evildoer, "Platform Timer Resolution" in the generated report.