Some machine with AMD video shipsets will seem very slow to turn on the screen on startup and after wake from sleep. This seems to fix it!
AMD power saver If you have an AMD graphics card, there is one more step you can try. Go to the Start Menu and type "regedit". Open regedit and click the Edit button at the top of the screen, then click on Find. Type "EnableULPS" and click "Find Next". EnableULPS will be highlighted in the list of registry options.
[Windows 10 - disable ULPS in Regedit]http://cdn1.expertreviews.co.uk/sites/expertreviews/files/2015/08/7_windows_10_regedit_disable_ulps_0.png?itok=iklKQW5O Double click it, and change the value from 1 to 0. This will disable a power saving feature that switches off your dedicated graphics card when it's not needed and this will mean your laptop consumes more battery power, so only do this if your laptop spends most of its time plugged in.