Gunner Asch wrote:

It largely depends on material, cutter type and material, rake, relief
and so forth. As well as machine rigidity, vibration, rpm etc etc

I second that and extend:
* coolant or cutting oil or dry cutting
* lubrication of lathe's bed and feed spindle.
* spindle temperature
* slightly clamping the saddle or not

and and an. It is not just the tool!

Re material:
I have some round (thanks good almost used up) that is nice to turn the
first mm, then there comes a region of 1mm that is a pain and then it gets
nice again.

Nick