There is a comprehensive system for copying and pasting the ‘history’ from one image to another and that is to be found on the right hand side menu of the lighttable. Select your image and while it is selected open up the history-stack the rest should be blindingly obvious.
If you are new to darktable you really need to invest some time in either reading the manual or looking at some basic videos (there are many), otherwise you will be wasting a lot of your time and that of others.
I run dt on a variety of laptops, some of which are quite small … so don’t blame your hardware. dt is highly optimised and even without OpenCL it is blindingly fast.