After running Drive Test program, I have information that my system is Excellent, but my pulse frequency is not stable. On 25kHz, Max Variation   is 17 uS. Is this normal?
Also when i'm joging with motor speed of 9000 mm/min, Real speed is smaller and it's variating between 8976 and 8990 mm/min. Pulse frequency is cosing it or this is normal?

Thanks,
Sashko

It should be fine at that, easiest way to check is test that you have not lost position on repeated runs. Also the sound of the motors tell you a lot, if they sound rough then you may have problems.
Hood

Thanks Hood,

Sashko