Eddy
2
There is only one answer to that question. Noone can tell 
It depends on a lot of things.
What cpu, hardrive, how many memory(ram), what is running, how many files are there, what are the settings in Avast, how much is the file system fragmentated and many more things like that.
If you really want an answer. It takes from the beginning till the end ;D
Almost forgot. WELCOME to this board.