386, introduced 1985:
http://www.cpu-world.com/CPUs/80386/Intel-A80386-16.html
Typical/Maximum power dissipation: 1.85 Watt / 2.3 Watt
And even no Pentium III 1999-2003 needed more than around 30 W:
https://en.wikipedia.org/wiki/List_of_Intel_Pentium_III_micr...