We describe self-starting high-power femtosecond laser based on crystal Cr4+:Mg2SiO4 producing 17 nJ pulses of 40 fs duration at 26.5 MHz repetition rate. This low repetition rate is achieved by employing one-to-one telescope in the cavity. The pulse energy is increased by 5 times in comparison with the short resonator laser. To our knowledge, it produces the highest energy ever achieved from this type of laser directly from the resonator without cavity-dumping or external amplification. We believe that this laser source can be used for many applications, including nonlinear optics, microscopic imaging and micromachining of silicon and other semiconductor materials. 2002 SPIE - The International Society for Optical Engineering.