Sparkfun 9DOF IMU M0 clock configuration for 1kHz sample rate

Sensors IMU & Motion
1

I want to get 1kHz from Accelerometer and Gyroscope

My settings

getIntStatus->1

getGyroFSR->2000

getAccelFSR->16

getLPF->188

getSampleRate->1000

getFifoConfig->0

dmpGetEnabledFeatures->0

getTapDir->0

serial baud rate → 500000bps

#include <SparkFunMPU9250-DMP.h>
#include <util/inv_mpu.h>

imu.setSensors(INV_XYZ_GYRO |INV_XYZ_ACCEL);

loop {
  mpu_get_gyro_reg(data, &time);
  SerialPort.print(data[0]); SerialPort.print(","); 
  SerialPort.print(data[1]); SerialPort.print(","); 
  SerialPort.print(data[2]); SerialPort.print(","); 
  mpu_get_accel_reg(data_2, &time);
  SerialPort.print(data_2[0]); SerialPort.print(","); 
  SerialPort.print(data_2[1]); SerialPort.print(","); 
  SerialPort.println(data_2[2]);
}

Nevertheless, there is no obstacle in the loop, I can get just 379 within 1 second (379 Hz).

My question is, How can I clock configuration on Sparkfun 9DOF IMU M0?

it doesn’t matter from an external or internal oscillator. I want to speed up the clock frequency for the purpose of a high sample rate.