In order to find hardware monitoring chips and temperature sensors, SpeedFan needs access to several resources on your motherboard. Some of them can be found on ISA. All PCs have got ISA, even if there is no ISA slot. Some other chips are embedded in the SuperIO chip. Some others can be found on the SMBus. In order to access the 2-wire SMBus (System Management Bus) serial bus, SpeedFan needs to communicate with other devices. SpeedFan recognizes and properly accesses the following BUSes:

		Supported BUSes
		BUS		Notes
		ALi M1533
		ALi M1535D/D+
		ALi M1543
		ALi M1563
		ALi M1573
		AMD 756
		AMD 766
		AMD 768
		AMD 8111 SMBus 1.0
		ATI Radeon 9100 IGP (IXP150)
		ATI SB300
		ATI SB400
		Intel 440MX
		Intel 6300ESB
		Intel 82801AA (ICH)
		Intel 82801AB (ICH0)
		Intel 82801BA (ICH2)
		Intel 82801BAM (ICH2-M)
		Intel 82801CAM (ICH3)
		Intel 82801DB (ICH4)
		Intel 82801EB (ICH5)
		Intel 82801FB (ICH6)
		Intel 82801GB (ICH7)
		Intel 82801HB (ICH8)
		Intel PIIX4
		Intel PIIX4E
		ISA BUS		An ISA BUS is present in every PC even if there is no ISA SLOT. A lot of legacy devices are connected to the ISA BUS. Several hardware monitoring chips are accessible through the ISA BUS. This BUS is much faster than any other SMBus.
		nVidia GeForce
		nVidia MCP04
		nVidia NForce
		nVidia NForce2
		nVidia NForce3
		nVidia nForce4
		nVidia nForce410
		ServerWorks OSB4		SF will return errors with this SMBus if it's not enabled, but it can properly access it if enabled. If you're getting errors, try to download a BIOS update first and try to enable ACPI in your BIOS.
		SiS630
		SiS635
		SiS645
		SiS645DX
		SiS648
		SiS650
		SiS651
		SiS655
		SiS730
		SiS735
		SiS740
		SiS745
		SiS746
		ULi M1689
		VIA VT8231
		VIA VT8233
		VIA VT8233A
		VIA VT8235
		VIA VT8237
		VIA VT82C596
		VIA VT82C596B
		VIA VT82C686A
		VIA VT82C686B

There are 58 BUSes listed here.