With the introduction of Intel's Pentium D and Pentium Extreme Edition dual core processors, microprocessors have reached new levels of power consumption and heat dissipation. AMD's dual core Athlon 64 X2 is power hungry as well, but usually does not come close to the Intel numbers.

However, it is not only processors that have been boosting energy consumption. Faster system clock speeds and ingredients such as quick memory controllers or PCI Express controllers require quite some complex logic and contribute to higher energy requirements themselves. As a result, only few core logic components on a motherboard can do without at least a passive heat sink today.

Likewise, modern 3D graphics silicon needs to be powered. Although the latest Nvidia GeForce 7800 GTX turns out to be more energy-efficient than its predecessor, it is still able to reach an energy turnover of more than 100 W under load.

But not everything is consuming more power these days. DDR2 memory actually runs a much lower voltage and consumes a bit less energy. Also, the transition from CRT monitors to TFT displays cuts display power consumption by half. Lastly, more and more power supplies are reaching efficiencies of 70% and more. Components such as hard drives or optical drives roughly consume the same power that they did a few years ago.

At the end of the day, the increased consumption of today's platforms easily exceeds the savings I just mentioned, which is why you should have a careful look on what you plan to buy if performance is not all that matters to you.