[jywang]

Installing Visual Studio 2013 with Phone SDK will cause Hyper-V to be installed which in turn disables the ability for CPU to run at a lower frequency. I manually turned-off Hyper-V after installing Visual Studio. You won't be able to use Windows Phone emulation while disabled but it allows the CPU to run at lowered frequency.

[vipkl]

Interesting, does the same thing happen if I simply install Hyper-V from Windows Features ("Turn Windows features on or off")? Or would I need to actually create and run a VM to be affected by this bug?

I assume it is a bug that will be fixed in the future, and not by design?

[azcruz]

How can enabling Hyper-V a bug?

[jywang]

Just installed affects CPU speed.

[chfhyh]

Interesting, at what frequency your CPU is running.. It is hard to believe Hyper-V would affect CPU just by installing it. do you have a source for this claim?

Installing Visual Studio 2013 with Phone SDK will cause Hyper-V to be installed which in turn disables the ability for CPU to run at a lower frequency. I manually turned-off Hyper-V after installing Visual Studio. You won't be able to use Windows Phone emulation while disabled but it allows the CPU to run at lowered frequency.

[jhoff80]

My understanding is that it doesn't actually change the CPU speed, but changes the reporting. (I could definitely be wrong on this though). Basically though, I think it basically abstracts the CPU from the OS, and then both the host OS and client OS only see a virtual CPU.

[vipkl]

Confirmed removing Hyper-V brought back the minimum/maximum processor state power management settings (under CP > Power Options > Changed advanced power settings > Processor power management).

With it installed, I did notice that the SP2 battery life seemed to have run down quicker.

Also discussed here (see 2nd page of that thread).

[azcruz]

Why would anybody run virtualization on low processor speed is beyond me.