Itocp.com measured the energy consumption of a full system with one of AMD’s 45 nm CPUs.
One of the 45 nm Phenoms, codename Deneb, with 2.3 Gigahertz clock speed had to compete with an equally clocked Phenom X4 9600 Black Edition. The chassis for the test system was a Microstar's K9A2 Platinum, a 790FX board, which was equipped with a Geforce GTX 280 and 2 GiByte PC2 8500 memory. The 1,200 watt power supply unit is from Thermaltake.
When running in idle mode, the Deneb needed 7 watt less than the Agena based system (147 vs. 154 watt). With a heavy workload the difference is noticeable bigger. While the system needs about 200 watt with the Phenom X4 9600 BE, the 45 Nanometer version needs 24 watt less. But the transition to the smaller architecture has another advantage: The temperatures of the Deneb are about 8° Celsius below those of the Agena CPU.