We present beam test results on single sided silicon microstrip detectors, with different substrate resistivities. The effects of radiation damage are studied on a detector irradiated at a fluence of 2.4 · 10 14 n/cm 2 . The detectors are read out with the APV6 chip, which is compatible with the 40 MHz LHC clock. The performance of different detectors and readout modes are studied in terms of signal-tonoise ratio and efficiency.