I just asked about performance monitor VS 2015 and got perfect answer. I wish there could be performance monitor available for SQL Server Management Studio also. Is it available for any version of SQL Server Management Studio? If yes where is it?
For SQL Server 2014 inside "Object Explorer" right click on the root node (your SQL Server instance) and select "Activity Monitor" from the menu:
or use the shortcut CTRL + ALT + A
or click the highlighted button in the toolbar:
More information here on Microsoft docs.