MPU6050 Axis Synchronisation

Hello,
I'm using the MPU6050
The I2C is working Great, i've got my 6axis result.
I've set the interrupt so i've got a pulse when the data are ready.
i'm using internal clock
All that woks quite well.

I've confronted my design to different other 6 axis motion sensors.
if a synchronise the result of my accelerometer to the data provided by the other sensor, i find myself with a time difference for the gyros axes.

To validate my sensor i need to know exactly where this time offset is comming from so ican correct my data.

Can Somebody help me?

Sincerly.

Minh