SpeedFan 4.27

skiabox · 8 Νοεμβρίου 2005

SpeedFan is a freeware program that monitors voltages, fan speeds and temperatures in computers with hardware monitor chips. SpeedFan can even access S.M.A.R.T. info for those hard disks that support this feature and show hard disk temperatures too, if supported. SpeedFan supports SCSI disks too. SpeedFan can even change the FSB on some hardware (but this should be considered a bonus feature).

At the lowest level, SpeedFan is an hardware monitor software that can access temperature sensors, but its main feature is that it can control fan speeds (depending on the capabilities of your sensor chip and your hardware) according to the temperatures inside your pc, thus reducing noise and power consumption. Several sensors, like Winbond's and the AS99127F support fan speed changing, as well as others from Maxim, Myson, Analog Devices, National Semiconductor and ITE, but the hardware manufacturer must have connected the relevant pins to some additional, yet trivial, circuitry. This means that if you have, say, a Winbond W83782D on a BP6 then you're ok, but not every motherboard with such an hardware monitor chip will be able to change fan speeds. From one of the very first hardware monitor chips that could be found in standard PCs, the National Semiconductor LM75 (and all of its clones, like the Philips NE1617 and the Philips NE1618 or the Maxim MAX1617) or the Analog Devices ADM1021, such chips have been greatly improved, both in their precision and in their capabilities. Current chips can monitor fan speeds, voltages and control fan speeds bu using PWMs (Pulse Width Modulation). Some chips can even be programmed to vary fan speeds without any additional software intervention. If your BIOS was programmed to setup such chips this way you can still try to use SpeedFan's Advanced Configuration to revert to manual (software controlled) mode. Winbond W83697HF, Analog Devices ADT7463, SMSC EMC6D102, ITE IT8712F, National LM85C and Maxim MAX6650 are very good candidates. Some SuperIO chips include temperature sensors too. SpeedFan can automatically detect them and use their features. The most used are National PC87366 and all of SMSC LPC SuperIO chips. SpeedFan can find almost any hardware monitor chip connected to the 2-wire SMBus (System Management Bus, a subset of the I2C BUS) Serial Interface and to the ISA BUS. SpeedFan works fine with Windows 9x, ME, NT, 2000, 2003 and Windows XP. SpeedFan can be minimized to the tray and is compatible with Motherboard Monitor 5.

A few numbers...

SpeedFan can:

handle almost any number of South Bridges

handle almost any number of hardware monitor chips

handle almost any number of temperature readings

handle almost any number of voltage readings

handle almost any number of fan speed readings

handle almost any number of PWMs

What is S.M.A.R.T.?

S.M.A.R.T. (or SMART) is a technology built into recent hard disks. If enabled, it lets the end user query the hard drive about its health and, eventually, performances. The end user (you) can access such info by using some specific software. SpeedFan can query those info for you. SMART reports, for example, if the hard disk has been used for too much time (thus reaching its expected end of life), or if it took too many attempts to start spinning, or even if too many read errors occurred. About every modern hard disk can report its temperature this way. They do have a temperature sensor that might be located inside the enclosure or somewhere outside it.

Please, note that SF might inform you that a reboot is needed in order to support SMART on your PC.

Will you ever add support for this sensor chip?

I asked for datasheets to some manufacturers, but with slow or no answer at all. Anyhow: since version 3.00 I'm ready to, easily, add support for new chips. I've got several chips to add. I will start adding detection for them: if you will get a message saying "PLEASE REPORT", please contact me and I will add support for it in a few days icon_smile.gif

Why can't my motherboard change fan speeds even if the sensor chip should be able to?

Even though the sensor chip might be able to change fan speeds, the hardware manufacturer still has to include some external circuitry. This is not always included. I'm able to know if a motherboard can change fan speeds, but not if it is unable for sure. You might try to contact the hardware manufacturer and let me know.

How can I identify my CPU temperature?

To find your CPU's temperature sensor you can leave your system idle for a few minutes, to let temperatures drop, and then go to 100% usage for a while. The temperature that rises faster is the one you're searching for. Other available temperature readings usually come from your sensor chip itself, from the southbridge, the voltage regulator, or even from an additional probe placed under the processor. This additional temperature sensor is not necessarily a duplicate. Some CPUs are not actually able to report the internal temperature from their die. To be able to read their temperatures, an additional external sensor (thermocouple) is used. In such cases, you will see two temperatures referring to the processor. The higher of the two is from the die. As a final note, please remember that not all available temperature sensors are actually connected to something. If you happen to read unusually high or low temps, they are likely to be from a disconnected (unused) temperature sensor.

My fans are showing odd RPMs or 0 when slowed down

Fan speed control is achieved by accessing some features available in some hardware monitor chip or some other special hardware. These chips might be able to controls fan speeds. They usually do this by using PWM output. A PWM digital ouput is a digital signal that alternates some levels very fast, thus simulating some intermediate average level. The net result is a perceived average voltage lower than the usual one. Please note that some chips (very few of them) are able to lower the voltage without PWM simulation.

The fans, on the other hand, can report their speeds (RPM) by using some internal sensors that report how often some current flows between two plates. Fans are built assuming nominal voltages and a continuous signal. When voltages are lowered or modulated through PWM, some fans are no longer able to properly trigger when those plates face each other and resulting fan speeds may show odd values. SpeedFan works flawlessly even in such situations.

Negative voltages are shown incorrectly

Hardware sensor chips are generic devices that can be used to measure voltages from anywhere. The measured voltage must be converted to the range required by the sensor chip. Standard monitoring chips specify which external circuitry must be used in order to measure voltages outside some range. Voltages like 12V, -5V, -12V and some others need this external circuitry. Some manufacturers chose not to follow datasheets. If this is your case, then you will read unusual values from SpeedFan. Since this custom circuitry is not known, SpeedFan does not try to "guess" it as any reading wouldn't be safe. If you get really odd voltage readings, simply enter configuration and uncheck the relevant ones.

How to install

Since the installer has been introduced, you simply have to run the EXE you downloaded and follow the installation process icon_smile.gif