Low power CPU options for 24x7 Windows server 2008

[StrandedPirate]

Looking to build a new server to replace an old 2003 windows domain controller. What cpu's would you recommend that are:
1) low power consumption ( very important )
2) x64 instruction set
3) 1.8Mhz or higher

 

[RobCrezz]

As it doesnt sound like its going to be doing a huge amount of CPU work, I would look at the i5-4670T, its quad core, 3.3Ghz and has a 45w TDP, which is very low.

You could go a little lower, but it would mean dropping to a dual core, which in the long term might leave you wanting.