Just curious...thanks!

It depends on the quality of the draft and how much time you (and your supervisor) want (or have) to spend on it
It also depends on whether you are writing completely from scratch, or have papers already, and how much you have already analysed your results.
I know someone who got a PhD (and is a successful postdoc) who gave it in without her supervisors reading it. I took ages to write and my chapters were 2nd or 3rd drafts. The one on the 3rd draft could have been improved further, and was twice the length of the others, but it was getting to my 4th year deadline. Some people want a near perfect thesis, others just rush it in and want to sort it out in the corrections as there probably will be changes anyway.

The day you can submit a paper without any revisions from your advisor, you'll get your PhD