I have 2 XML files for the same machine. One is moving very smooth while cutting path consisting very small lines while the other one runs jerky . I can't find the reason.  I'm attached both files. and sample g-code

Additionally as I dropped the kernel speed machine cuts faster . for example at 100khz  300unit/min  at 25000 around 1400 units /min.   What a relation???

First ting to say is in most cases it is wise to keep the kernel to the minimum required. The reason is that the higher the kernel the more resources it grabs and the less time your computer has to do other things it needs to do, this can lead to erratic pulses and lost steps.

Looking at your xml, the Jerk one, the first thing that struck me was the supersonic rapid speed (Velocity) you had set in motor tuning, it was set to 10,000 inches per minute. I then looked at your smooth profile and I see you have that one set to the same but your native units are set to metric rather than imperial. This then makes the 10,000 units per min a more realistic Velocity.

So two things, first keep the kernel to the lowest that you require and second is you need to change the native units to mm in your jerky profile (config menu, Native Units) That is assuming that is what you wish to work in, if not your Velocity is unrealistic for Inch units.

Hood