Check Power Plan
Yes, my power plan is set to high performance.
No, my power plan is NOT set to high performance.
Overview
A power plan in Windows 8 is a group of settings, such as screen brightness, adaptive display, processor state, and modes, such as hibernate and sleep that together decide how a computer performs and uses power. Performance of a computer is linked to the power plan in use. Therefore, while troubleshooting computer performance, you should check the power plan in use to ensure that it is not affecting performance.
Checking the Active Power Plan
To check the power plan that is active on your computer, you need to perform the following steps:
1. Press the 
+ I keys on your keyboard, and then click Control Panel that appears on the right side of your desktop screen.
If you do not have a key on your keyboard, click here.
2. Type Power Options in the search box.
3. Click the Power Options link.
4. Observe the power plan in use in the Power Options window that appears.
5. Click the 
icon to close the Power Options window.
Summary
Power plans decide how Windows should balance between power usage and performance. If you require high performance in a computer, set the High Performance power plan, as described here. For the High Performance power plan, Windows attempts to get the best possible performance at the cost of power consumption.