until today i heard about the tool speccy
remember that these tools usually develop their own drivers to talk with the motherboard sensors and provide a reading
as you see, bios has its ways, hwinfo has another, speccy has a different one
in some motherboards hwinfo will give problems, but is very uncommon to have problems with hwinfo, so i tend to trust it alot
there are cases where the problem is not the driver or the tool but the sensor itself, sometimes motherboard manufacturers use cheap bad quality sensors, so values are reported poorly, i had a old athlon x4, the system said cpu was at almost 60°c, but heatsink when i touched it, was really cold, so that sensor was giving bad reports, even under bios
so you can encounter all these situations, what is important is that you check, but use different tools, don't depend on only one tool to do things, because these tools are made by small teams of developers, or even can be developed by only one man, so the tools can't be all the time up to date and work perfectly always everywhere