During the early 1980s, geoscientists worldwide realized synchrotron radiation was a highly valuable tool for in situ experiments, i.e., experiments under simulated Earth mantle conditions. MAX80 at Deutsches ElektronenSYnchrotron (DESY) – HAmburger SYnchrotron LABor (HASYLAB), Hamburg, a single-stage multianvil DIA system at a synchrotron beam line was among the high-pressure pioneer apparatus designed in Japan. MAX80 is equipped to perform ultrasonic interferometry in conjunction with synchrotron radiation measurements, i.e., X-ray diffraction (XRD) and X-radiography. The maximum conditions are ∼12 GPa at 2000 K. To make transition-zone conditions accessible and to achieve bigger specimen volumes, the sister apparatus MAX200x, a double-stage DIA system, was recently installed at the HASYLAB HARWI-II beam line. MAX2000x is designed to reach 25 GPa and 2400 K, simultaneously. MAX200x is driven by a hydraulic ram with a maximum load of 1750 tons. Derived from the successful equipment of MAX80 and adapted to the new task, MAX200x is equipped for XRD with a Ge-solid-state detector, for transient ultrasonic interferometry, and it has a radiography system to measure change of volume and shape of the sample under in situ conditions. A stepper motor–driven slits system allows the X-ray beam size and shape to be optimized for experiments. Parallel to the installation of MAX200x, some experiments were carried out to improve the potentials of multianvil apparatus in terms of maximum pressure and limitation of stress inside the sample and the anvils. Some recent results of these experiments as well as the data from the first experiments with the new double-stage system are reported here.