"The data transfer rate of a DVD drive is given in multiples of 1350 kB/s,"

So on a great day, when all is (never) perfect day without any delays for fixations, finalizing or such the 1X drive makes your DVD in ... 3,482 seconds or 58 minutes.

That 8X, in theory could dive under 8 minutes, but I see 10 to 20 for the full 4.7GB write everytime.

Try better software.

Bob