Most efficient dualcore processor

Hi,

I'm new here, and my English is really bad, so please forgive me when I'm making mistakes.

I'm planning a home server together, so I need the right CPU for it.
It must be powerfull enough for extracting archives and therefore I wanted a CPU that has a clock of atleast 2 GHz.
Thet Intel Atom N330 is too slow, so I went to the AMD side, I found a Athlon 64 X2 4850e and 5050e.

Now my question is: Which processor should you advice me for my homeserver?
Doesn't there exist an Intel version of the 5050e, or something like that?

I really hope you could help me out.

I saw the 250 has a TDP of 65 and the 550 BE has a TDP of 80....
I need to pay the energy my homeserver uses myself, my parents don't want to do thas, so I really need a good balance between low power concumption and performance.
On a benchmark at hardware.info I saw the 250 uses Idle +- 140Watt, I think/hope that that is including the graphics adapter, hdd and mainbord.
How many do you think that processor uses at its own?

Thanks for your replay btw,
theblindman.

I've tought about that, but a laptop with a dual core processor faster then 2 ghz gets pretty expensive.
I've searched for a motherboard that can take a mobile cpu, but there aren't much of them and if there are, they don't have more then two SATA ports...

Thanks for your replay...

Oh, one thing more: which hardware site do you prefer for hardware info? I'm seartching for a site that gives me the really consumption of a processor, not the whole system.

The slower Intel 45nm duals don't use anywhere near their 65W TDP.

well, whatever processor you get, you could downclock and WAY under volt the processor (less volts and less speed, less power used)