The disk works fine under Windows 7 (and I assume Windows 8 as well): fast, quiet, no complaints. However, Ubuntu 13.04, a "click" occurs at regular intervals in idle. This noise corresponds to parking the disk head (head parking) that occurs after a period of inactivity for security reasons, to prevent it from coming into contact with the playing surface in case sudden movements or collisions. This phenomenon can be verified by consulting the dedicated SMART value (load cycle count): it increases by one for each head yardage. Now this head parking phenomenon also exists on Windows, but is relatively quiet and unnoticed, while on Ubuntu, the "click" is heard (as if the movement was much net) and quickly becomes annoying or unbearable. This suggests that this record energy saving management is not optimized for Linux, at least Ubuntu. It is possible to correct more or less this problem by changing the value of "timer" (idle period before the park is triggered), through the wdidle3 findable utility on the WD website, by extending it to 300 seconds maximum, however, it is clear that this solution is not optimal. In addition, this solution is applicable only when the notebook is on AC power. On battery "clicks" will always be heard. Overall, a very good record, but the compatibility / Linux optimization should be reviewed.