I have a Dell Inspiron 5160, and I recently installed SpeedFan to monitor the internal temps. After installing it, and selecting "Dell Notebook" under "Options", it displayed three temperature sensors: HD0, CPU, and Temp1. HD0 and CPU are obvious, but I'm not sure where it's reading Temp1 from. If I go under "Configure" here is some information it has for Temp1. Chip: ACPI BUS: ISA Address: $0 At idle, it's about 50C, which seems too hot to simply be some internal case temperature.