It looks like the only official/reliable information available is the Thermal Design Power (TDP), this figure gives only a very limited view of the overall power consumption: the TDP (as defined by Intel) is a metric of the chip CPU/chipset power consumption under relatively high load (not worst case tough!). This number is especially relevant to the OEMs in order to properly design the system cooling.
It is interesting to see that the new Atom N450 got a TDP of 5,5Watt, while Atom N270 and N280 got a TDP of 2,5Watt.
The higher TDP is justified by the new Pine Trail architecture: beside CPU core and caches, the main chip (Pineview) integrates memory controller and especially the graphics engine.
In the first Atom platform memory controller and graphics subsystem where integrated in a dedicated chip (945GSE) connected to the main chip (Atom N270/N280) via the FSB.
In both platforms the I/O is provided by a separate chip: NM10 for the Pine Trail and ICH7M for the first Atom generation.
TDP for Atom N270/N280 vs Atom N450
If you consider the platform TDP you see that the overall TDP is lower in the new Pine Trail platform
- TDP for Pine Trail: 5,5Watt (Atom N450) + 2,1Watt (NM10) = 7,6Watt
- TDP for first generation Atom: 2,5Watt (Atom N270/N280) + 6Watt (945GSE) + 3,3Watt (ICH7M) = 11,8Watt
This relatively high TDP difference is due especially to the fact that the 945GSE was a pretty old design, cheap enough to be used in netbooks. If I well remember Intel's original plan was do deploy Atom with the GN40 chipset: as of today I don't find anymore any information on the Intel website about this chipset.
In a future post I'm going to add a comparison to the Nvidia Ion chipset.