SpeedFan 4.51 added support for 5 PWM controls on the ITE IT8620E. This chip is a custom one
made by ITE for Gigabyte and no datasheet was available. After several tests on multiple
motherboards, SpeedFan became able to control the speed of up to 5 fans using PWM. The first
3 PWMs seem to follow the standard behaviour of other ITE chips and, depending on BIOS
settings, might just need their PWM MODE to be set to SOFTWARE CONTROLLED in CONFIGURE /
ADVANCED. PWM4 and PWM5, on the other hand, appear to behave differently and have no
corresponding PWM MODE to set. Unfortunately, Gigabyte seems to have implemented fan control
in different ways across his range of motherboards and it has been reported that
changing
PWM4 using SpeedFan leads to a PC power off on some of them. On many others, the majority
at the moment of writing, PWM4 works great to change the speed of one of the fans.
To let all users enjoy the widest range of features offered by SpeedFan, two new advanced
settings have been added:
- PWM 4 Enable
- PWM 5 Enable
Those settings are disabled by default and will be enabled only if PWM4 and/or PWM5 will be
reported as safe to use in specific motherboard models (for example, on the Gigabyte Z97-D3H
they work great).