Can anyone speak to a comparison between the Celeron G530T/540T/550T and the G1610/20T?  All are 11544, but I'm looking for Sandy Bridge vs Ivy Bridge.  Looking for super lower power.  This is for a file server, so horse power needs are minimal (however dual cores would be a plus for repurposing the machine at a later date if need be)

Specs list 35w TDP on all CPUs, just trying to figure out which family will consume the least amount of power and generate the least amount of heat (small case, planning on a passive heatsink if possible)

Thanks

Ivy bridge should beat sandy bridge.

There is also this haswell option:

http://www.newegg.com/Product/Product.aspx?Item=N82E16819116947

As said above, the newer generations will eat slightly less power than previous ones.  However, all of them being 35W TDP, the fact that they will see VERY little use mean that they will use very similar figures in reality - probably within a very few watts of each other.

By the time you figure out all of the other draws in your system, the difference in power between those CPUs will be negligible.