Decreasing Power Consumption

Decreasing Power Consumption

To solve the problem of limited capabilities in a computer system, you can upgrade the existing system or purchase a new computer. The second approach can be expensive. Because of this, most experienced and thrifty PC users choose to upgrade.

As a rule, all manipulations related to an upgrade can be performed on your own or with the help of support specialists. Usually, you must purchase and install new adapters and a new processor. Most PC users choose a newer model of the same product line, which ensures higher performance. You often can return the previous processor to the vendor and get a rebate.

However, this approach can lead to unexpected problems. Most components are retained in the system during an upgrade. The list of such components is long and includes the power supply unit and the motherboard. This can become a source of trouble.

Powerful processors consume significant power. For the latest models, this parameter has approached 100 W. Rapid growth of power consumption has forced processor manufacturers to introduce changes into Voltage Regulator Module (VRM) specifications and motherboard architecture. In the past few years, such changes have been introduced several times. Recommendations have involved power supply units. Newer devices are released according to new specifications, but most devices released earlier fail to satisfy such requirements.

Adding new components and replacing the processor can increase energy consumption to such a degree that the supplied power might be insufficient.

The thermal power of the newest models of Intel Pentium 4 processors, with clock frequencies of 3 GHz or higher and 0.13-micrometer technology, is more than 80 W. AMD products keep pace with Intel processors in this area.

Powerful processors whose consumption current exceeds 60 amperes place a heavy load on transformers, rectifiers, and stabilizers.

The load on the computer's power-supply unit includes several factors typically overlooked not only by end users, but also by many specialists. The real efficiency coefficient is far from 100%, and the load reactive component, related to a parameter known as cosϕ, is a factor. Including these, the power consumed by the processor from the power supply unit can be increased 1.5–2 times. This is a large share of the nominal power of the power supply unit. Still, other loads also consume considerable power, such as the video adapter and hard disks. When implementing RAID 0+1, the system must have no less than four physical hard disks.

These components and others require great power for their operation and have intensive heat emission. Like the processor, they are not exclusively active loads for all sources, including the power supply unit. When they are active, the consumed power increases significantly.

When relatively low power supply units or motherboards are used, whose transformers do not ensure the required values of electric power, the system might become unstable. Replacing a component with a more powerful model only worsens the situation. In some cases, this might result in total failure. This might occur only when performing specific kinds of operations, such as intense calculations or CD/DVD writing.

The powerful processor consumes the lion's share of the power; therefore, it is possible to overcome the problem of insufficient power by anti-overclocking the processor (i.e., by reducing its clock frequency).

As previously demonstrated, the thermal power of semiconductor circuits, including that of the CPU and graphic processor, depends on the supply voltage and on the clock frequency:

Pf = Po × (Vf/Vo)2 × (Ff/Fo)

Here, Pf is the thermal power at the f frequency, Po is the thermal power at the nominal frequency, Vf is the supply voltage at the f frequency, Vo is the supply voltage at the nominal frequency, Ff is the value of the current frequency, and Fo is the value of the nominal frequency.

From this formula, it follows that power grows with the frequency and, conversely, decreases with the frequency. Furthermore, to retain stability of operation, it is necessary to increase the supply voltage with the frequency. If the frequency is decreased, it is possible to decrease the supply voltage. Taking into account this relationship greatly decreases thermal power and energy consumption.

This method is widely used in portable computers to reduce power consumption and prolong battery usage.

With desktop computers, the reduction of power consumption is not as urgent. Besides this, reducing the clock frequency also reduces system performance, which lowers the value of upgrade. Nevertheless, this approach can help you detect the causes of unstable operation. Furthermore, if the system becomes unstable only when performing specific tasks, related to operation of specific components with high power consumption, temporary anti-overclocking can help you circumvent the problem of insufficient power supply.

Finally, anti-overclocking reduces the load on the tools that support optimal temperature modes required for the operation of hardware components. This allows you to reduce the power of cooling fans, which reduces noise — frequently an urgent problem.