Newer CPU and motherboards have far better power management. A simple build with a intel G3420 (http://ark.intel.com/products/77775/), running a SSD and a 92% (gold 80+ rating) power supply will use <60 watts at 100% load and be many times faster than any pentium D. Many of the systems pictured in this thread will have idle power consumption <20 watts AC, some of the 7xxx and R-series cards use <2 watts at idle.