3. The Eternal Debate: Desktop Or Notebook CPU?

The advantages of a mobile Intel CPU are as clear as day. Less power consumption and special power-saving features, such as Enhanced Speedstep, permit longer battery life and thus greater mobility for the user. In addition, the lower power consumption results in lower heat release from the processor. Accordingly, the processor's cooling system has slimmer dimensions and is less power-hungry (and quieter). It seems that the use of mobile CPUs means that notebooks can come in smaller packages. But why use a desktop CPU in this notebook? The answer to that is simple: the desktop CPU is considerably cheaper.

Or, put another way: if a manufacturer wants to aim for a certain price, it has two possibilities. Either it can use a mobile CPU and cut corners with equipment, or it can lavish the mobile PC with wide-ranging accessories and a desktop CPU. Nevertheless, the customer still has to accept some restrictions as far as mobility goes. But the loss of mobility is not as severe as often claimed. In normal operation, a notebook with a mobile CPU (using the processor's power-saving modes) runs on average 30 minutes longer than a device with a desktop CPU. A good design can mean it can run for up to 50 minutes longer.

The relatively slight difference in operation time is easily explained. On the one hand, on the face of it, the CPU running in normal operation (running typical office applications) has little to do, so power consumption (known as "average power") is far under the Thermal Design Power for mobile and desktop CPUs. On the other hand, the processor is not the only energy consumer in a notebook. Using up 30 percent, the display accounts for a huge chunk of the energy needs of the entire system. The graphics processor and memory modules also prove themselves voraciously hungry for power.