/dev/sdb: WDC WD1600AAJS-60Z0A0: no sensor <-- system/boot /dev/sda: WDC WD10EARS-00Y5B1: 36°C /dev/sdc: WDC WD1002FAEX-00Y9A0: 37°C Not much higher than yours Paul... The WD1600AAJS-60Z0A0 is no more than a month old. lm-sensors and smartmontools installed too.