Use minimum Vcore for cpu, to save electricity & aircon bills.

E.g. an Athlon LE1620 default Vcore is 1.25v, but @ default
200 mhz x 12 just 1.025v is needed : if 45watt is used @1.25v,
then just ( 1.025 ÷ 1.25 )² = 67.24% or 30.25watt is used. In
dos ( GUI too if no cpu driver is loaded ), user can underclock to
200 mhz x 5, then just 0.95v is needed : ( 0.95 ÷ 1.25 )² x 5/12 =
24.06% or 10.83 watt used.
Similarly ( @ default speeds ) a Sempron 1.6 ghz needs just 0.95
v, a Barton 2500+ needs just 1.35v. Same in Duron & K6III.
Lower Vcore & cooler cpu means less heat for mboard chipsets /
cache / hdd IC`s too so all will work faster & last longer. Users
also need not buy bigger PSUs, so save money there too. Higher
Vcores are needed only if users overclock CPU til the default
Vcores are not enough.

User cannot easily use lower Vcore if mboard does not offer
lower Vcore choices : these mboards waste electricity & aircon
bills for many years, so don't buy them. Some brands ( e.g. Giga
byte / MSI / Foxconn ) don't offer lower Vcores because very
few users know this way of reducing useless heat & saving
electricity etc.