It is probably because Genymotion uses x86 instructions and is using your processor Vt-x features and rendering the graphics hw accelerated.
It is a huge difference from the emulator that runs arm code under Windows.
Using VBox you can create a vm with the same setup and other version of Android x86. Do not forget to install the win drivers for your HW virtualization. Intel Core uses VT-x, but you have to install the module under the SDK Manager and then run setup from the file location.
MCP
