SDC2150 Problems to set max velocity

I\'m trying to control my two motors with the SDC2150 connected via USB to my pc with Ubuntu.

If i use Roborun software (on windows) and i use the commandmy two motors are able to run at their maximum speed.

On the contrary, if I use Linux API on Ubuntu and i send the command
both motors runs correctly, but they not reach their maximum speed.

Can someone help me to understand why i have this problem, please?

the !M _M _MOTCMD command is followed by the the power level for motor 1 and 2

example _M 500 600

the !G _G _GO is followed by the channel number and the power

example _G 1 500, _G 2 600

Thanks for the reply.

Can i ask you what\'s the range for each command, please?

For example, _GO and _M take values from 0 to 1000 for the power?

Is it the same also for the _ACCEL and _DECEL commands?