SpeedFan es un programa gratuito (freeware) que monitorea voltaje, velocidad de ventilador y temperaturas.

SpeedFan puede llegar a la información S.M.A.R.T de discos duros que lo soporten para mostrar la temperatura de discos duros, también. SpeedFan hasta puede cambiar el FSB en algunos hardwares. Poniéndolo de una manera simple, SpeedFan es un programa que monitorea tu hardware, puede tomar información de los sensores de temperatura para mostrarlas, pero su característica principal es que puede controlar la velocidad del ventilador (también depende de las habilidades del sensor y el hardware, no solo del programa), para reducir el sonido y el consumo de energía.

Que hay de nuevo:

4.33

- completely rewritten the detection and the identification strategy of ITE IT871xF chips (fan readings are now ok)
- xAP support is now properly reenabled between sessions
- fixed context sensitive help (F1 key) on Windows Vista
- enabled, if needed, the SMBus on Intel ICH7 and ICH8-M
- added several checks to CPU usage routines, fixing a nasty issue where an error window appeared once every second
- added full support for ATI SB600 SMBus
- added full support for Intel ICH9 SMBus
- added full support for nVidia MCP55 SMBus
- added sull support for ADT7475
- added nVidia Control Panel access to read video card temperatures
- supported the IT8716F and the IT8718F hardware monitor at unusual addresses
- added some SMB scan exceptions for Compal 08A0
- SMBus address $15 no longer scanned on AOpen i975Xa-YDG
- fixed an issue that caused the DFI LP UT NF4 SLI-DR Venus to power off on program start
- added support for Fintek F71872F voltage readings
- IT8712F-J now uses two undocumented FAN DIVs
- speeded up Asus M2N32-SLI DELUXE program startup
- added detection of an unknown Fintek chip (to avoid false detection of other sensors at the same address)
- W83627EHF and W83627DHG now properly show SMARTFAN III in CONFIGURE / ADVANCED
- W83627EHF and W83627DHG can now change PWM TYPE from PWM to DC in CONFIGURE / ADVANCED
- fixed FAN DIVISOR settings for Winbond W83791D
- added PWM OUT BASE CLOCK selection for WINBOND W83627DHG, W83627EHF and W83627EHG
- warning temperature can now be set as high as 125C in CONFIGURE