This is actually kind of ‘Fake News’. 
Because this tip will advise you to disable part of a scheme that’s best disabled all together! “Fast startup” is part of the hibernation scheme. It caches system files so your computer will start faster when coming out of hibernation. If you don’t see this option you probably already have hibernation disabled? But a good way to check is to see if you have the file Hiberfil.sys in the root of your C: drive. ( You need to have ‘view hidden/system files enabled’ for this!) For our purposes it’s best to disable the hibernation option all together. So if you see this file and clearly haven’t done so already just open a system prompt (cmd) with ‘admin’ rights and type the following command: powercfg.exe /hibernate off
Now restart your computer and you’ll see you got rid of the gigabit consuming file Hiberfil.sys. And you got rid of this horrible resource consuming hibernation scheme all together.