New submitter NotDrWho writes: As reported by Ars Technica: "With this week's official launch of Valve's Linux-based Steam Machine line (for non-pre-orders), we decided to see if the new OS could stand up to the established Windows standard when running games on the same hardware. Unfortunately for open source gaming supporters, it looks like SteamOS gaming comes with a significant performance hit on a number of benchmarks." They tested with two graphically intensive titles from 2014, Middle-Earth: Shadow of Mordor and Metro: Last Light Redux. They say, "we got anywhere from 21- to 58-percent fewer frames per second, depending on the graphical settings. On our hardware running Shadow of Mordor at Ultra settings and HD resolution, the OS change alone was the difference between a playable 34.5 fps average on Windows and a stuttering 14.6 fps mess on SteamOS." Even most of Valve's own games took big performance hits when running under SteamOS.