SpeedFan 4.41

SpeedFan 4.41 (freeware)

SpeedFan is a program that monitors voltages, fan speeds and temperatures in computers with hardware monitor chips.

SpeedFan can even access S.M.A.R.T. info and show hard disk temperatures. SpeedFan supports SCSI disks too. SpeedFan can even change the FSB on some hardware (but this should be considered a bonus feature). SpeedFan can access digital temperature sensors and can change fan speeds accordingly, thus reducing noise. SpeedFan can find almost any hardware monitor chip connected to the 2-wire SMBus (System Management Bus (trademark belonging to SMIF, Inc.), a subset of the I2C protocol) and works fine with Windows 9x, ME, NT, 2000, 2003, XP and Windows Vista. It works with Windows 64 bit too.

Scren Shots

SpeedFan can handle:

almost any number of South Bridges
almost any number of hardware monitor chips
almost any number of hard disks
almost any number of temperature readings
almost any number of voltage readings
almost any number of fan speed readings
almost any number of PWMs

How fan speed changing works
SpeedFan monitor temperatures from several sources. By properly configuring SpeedFan, you can let it change fan speeds based on system temperatures. When choosing parameters for the minimum and maximum fan speed, try to set them by hand (disable all the VARIATE FANs checkboxes) and listen to the noise. When you hear no noise from the fan then you can set that value as the minimum fan speed for that fan. I suggest to use 100 as the maximum value, unless you hear a lot of noise from it, in which case you might reduce the maximum speed to 95 or 90. You can set, say, 60 as the maximum value and, sometimes, I myself set it that way. Consider that when the WARNING temperature is reached, theprogram sets the fan speed to 100, whatever maximum speed you selected. One last word should be said regarding the USE FAN x listbox. In my pc, more than one temperature changes when a fan runs faster. You can configure on which fan every temperature should rely. On my system, TEMP1 and TEMP3 are both influenced by FAN1.

Disclaimer
This program is aimed at the power user. At those who know what they're doing. I've known of no real problem caused by SpeedFan, but may be it's due to the fact that once it made the PC explode and the user disappeared in the blast, thus being unable to report :-) Anyway: SpeedFan can be extremely useful, but you should first watch its behavior before setting and forgetting it.

4.41: