By default, the pump will ramp up to maximum speed (settable in the filter menu) and stay there as long as solar is engaged.
However, you can also allow the motor to run on low speed during the solar period if so desired. When solar low speed is enabled and solar is triggered, the pump will run at max speed for about 3 minutes and then step down to low speed. But that will only work if the VRV is installed at a fairly low elevation.