It's fair to say that fan speeds on our launch model ratchet up to a distracting degree during play, especially so with games like The Last of Us Remastered. One of the worst offenders as of late is Rocket League - an Unreal Engine 3 game that cranks the older CUH-1000 PS4 up to 63.7 decibels (dB) on our sound meter (as tested while upright on a wooden desk, and viewing a 4v4 match in spectator mode). Our sensor takes its reading from a centimetre behind the console's back vents, recording the fan at its top-most RPM - and it's fair to say that the high-pitched whine is a distraction even from a few metres away.
By comparison, the C-Chassis PS4 makes a real difference. In starting the console under the exact same testing conditions, Rocket League doesn't rise much higher than 51.2 decibels on the meter. This puts the new PS4 model at 12 decibels quieter overall in this close-proximity test. Though we're unlikely to get so close to a PS4 vents in reality, the difference is tangible at a regular playing distance from the console. At full speed, the launch PS4 is audible from across our office - a louder presence with higher pitch and volume. The new model is far from whisper quiet, but the fan isn't nearly such a distraction at max velocity.
It's a big improvement, and one that holds up in other tests. For example, our disc-based version of Metal Gear Solid 5 starts off loud on each PS4 as the optical drive initially caches data to the HDD, but this ceases after five minutes of play. Once settled, the C-Chassis gives a six decibel lead over the launch PS4 here, from 62.2 dB down to 56.2.