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My motherboard is an HP P4SD, and in the BIOS I found SMBUS in the Security tab. There is also something like "Device security."

There's a list and the value of SMBUS is "Hidden." That means that no Operating System will know about it (the device is disabled).

What is SMBUS and why is it disabled? How can I use this thing?

After this ive restarted BIOS settings and SMBUS was disabled by default.

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up vote 8 down vote accepted

The SMBus is the "System Management Bus".

It's an Intel-defined chipset feature for reporting things like fan speeds, motherboard temperatures, serial/model numbers, etc., to the OS.

Often there will be a monitoring utility provided by the motherboard manufacturer that takes advantage of the SMBus. You can also use it with programs like SpeedFan.

More info is available at Wikipedia and

As for why it's disabled, that's hard to say; maybe someone disabled it, or possibly it's disabled because Asus doesn't offer a monitoring utility for that board, so they turn it off by default to preserve resources.

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Windows installed it. Cool, it works! – Little Helper Aug 1 '11 at 14:46

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