We have investigated the efficiency and the noise occupancy of a double-sided silicon strip detector, which was subjected to non-uniform proton irradiations up to a maximum equivalent fluence of 5 . 1013p . ~m -~. The depletion voltage, varying over time due to controlled annealing, was close to zero on one end of the 6cm strips and 19OV at the high radiation end. We have determined the efficiency and noise occupancy on both n-side and p-side in a lo6Ru telescope, using a binary read-out system with 22ns shaping time.The n-side exhibits superior performance after type inversion.