In general, when I have a lot of rows to delete, I do it in a loop with a "wait". The advantages for me are:

Small chunks so I can see it progress.

Does not hog the system completely

Can be stopped & restarted without starting over

It may not be the fastest method, but in my case I needed to run it on a production server with minimal impact on others. Experiment with delay time & delete size

basically i set it up like this:

DeleteMore:

waitfor delay 5 seconds (to give others some cpu)

delete top 10000 from tableA where ......

if @@rowcount > 0 goto DeleteMore