  The Silicon Strip Detector (SSD) is a fundamental part of the Inner Tracking
System (ITS) for the ALICE experiment. Since the early phase of proton-proton
collisions at LHC, the SSD is fully operational and participating in the
charged particle detection and identification carried out by ALICE. The
performance of the SSD during the 900 GeV and 7 TeV collision data taking is
presented here. The stability of the system is monitored through the time
evolution of its calibration parameters and their correlation with the
environmental conditions. The intrinsic noise of the 2.6 million channels
composing the SSD is used to assess the detector efficiency. Finally the
performance in terms of hit reconstruction and energy-loss measurement is
discussed with reference to the global tracking and the ITS-standalone particle
identification carried out in the first collision events.
