The CBM (Compressed Baryonic Matter) experiment being built at the FAIR facility in Darmstadt, Germany aims to investigate the QCD phase diagram at high-net baryon densities and moderate temperatures. The FAIR accelerator will provide high-intensity heavy-ion beams for this fixed target experiment. To ensure the best operability of CBM at day one, a prototype of CBM has been set up, including scaled-down versions of almost all the detectors later to be employed in the final CBM setup. One main goal of this prototype called mini-CBM (mCBM), is to establish the free-streaming readout scheme envisioned for CBM. To test this scheme a dedicated test beam time was carried out at the beginning of 2024.

This contribution will focus on the mRICH detector, being part of mCBM. The mRICH is a proximity-focusing RICH detector using the same read-out electronics as the RICH detector in the final CBM experiment. Special focus is given to its timing performance which is crucial for a free streaming read-out setup.
Furthermore, its general performance is discussed, depending mainly on the aerogel radiator being in operation for more than four years.