Power Supply Product Guide

Power Supply

While the notebook PC has been raging in popularity, the desktop PC is still reigns as a powerhouse. Today and tomorrow offer new challenges to the computer. Video and High-Definition Video downloading has become more promising. Games have become more demanding. Desktops need to upgrade technologies for greater processors, processing speeds, memory, storage capabilities, graphic and sound processors. All these things translate to bigger power demands. One of the nice things about desktops is the inner components are accessible and may be upgraded.

A Power Supply Unit (PSU) is an overlooked part and yet it's the source of so many computer woes. That's because the PSU is an internal component inside the tower of your desktop PC. Yet its power rating capacity is vital when you place many multimedia demands on your computer. It's a sneaky sort of thing. You never quite know the power demands of the peripherals you add on.

An NVIDIA GeForce 9800GX2 PCI-Express video card recommends a PSU of 750 watt capacity or greater. An inadequate power supply will degrade the card's performance. In some cases it won't work at all. If you decided to upgrade the main processor of your PC, the new processor may also require more PSU capacity. A power supply unit (PSU) is one of the most critical parts of your computer. It supplies power to all of the circuitry inside your computer and must do so at the precise voltage. A poor-quality PSU (or a PSU with insufficient wattage) can result in sudden rebooting, hardware failure, and not being able to turn on your computer. Many factors should be taken into account before deciding on your PSU model and wattage, including your CPU type, graphics card requirements, and what exactly you will be using your PC for.

Temperature also greatly affects the lifespan of many components in your PSU, including your capacitors, resisters and fans. Generally speaking, when temperature decreases 10°, your PSU's lifespan will increase by about double. For example, if your output capacitor normally has a 3,000-hour lifespan at 105°, at 95° it will last 6,000 hours. However, for output efficiency, the same rule of thumb does not apply. Some PSU components achieve higher efficiency at lower temperatures, while others are the opposite. The point is, however, that an inadequate power supply may actually make your computer's circuits burn hotter. That can contribute to reduced lifespan of your system.

A PSU usually has a built-in fan to help keep the power supply running as cool as possible.


There are many different manufacturers of computer power supply units. Depending on its source, PSU ratings didn't have a rigid standard to follow. 80 PLUS is an innovative, electric utility-funded incentive program to integrate more energy-efficient power supplies into desktop computers and servers. The 80 PLUS performance specifications require power supplies in computers and servers to be 80% or greater energy efficient. This makes an 80 PLUS certified power supply up to 33% more efficient than current power supplies and translates to annual energy savings of approximately 85 kWh/year in desktop computers and 300 kWh/year in desktop-derived servers.

80 PLUS now certifies power supply products for high efficiency performance in server applications with the inclusion of a category of testing for Redundant Single Output server power supplies. Industry efficiency performance has improved dramatically over the four years of 80 PLUS' existence enabling 80 PLUS to announce higher efficiency levels of Certification (Bronze, Silver, Gold).

A PSU that meets an 80 PLUS certification is dependable to (at least) an 80% efficiency rating and measures a higher level of reliability.

Go for the Watts

With increased multimedia availability over the web, it's likely that your PC may play bigger roles at viewing and delivering high-definition video. Some video download libraries already transfer 1080p quality for view on your PC or transfer to your HDTV screen. This, often, requires a higher performance video card and these cards require a PSU with higher capacities. That capacity is rated as 'watts'. More watts mean greater likelihood to keep up with newer technologies.

Universal Input

Thinking about taking your desktop around the world? A PSU with Universal Input can be used in any country around the world within VAC90V~240V, without having to adjust the input power select switch.

Active PFC

Increasingly, switched mode power supplies (SMPS) are designed with an active power factor correction (PFC) input stage. This is mainly to meet new regulations aimed at restricting the distortion of the load current drawn from power lines. Both users and power companies benefit from PFC, as does the environment.

The preferable type of PFC is Active Power Factor Correction (Active PFC) since it provides more efficient power frequency. Because Active PFC uses a circuit to correct power factor, Active PFC is able to generate a theoretical power factor of over 95%. Active Power Factor Correction also markedly diminishes total harmonics, automatically corrects for AC input voltage, and is capable of a full range of input voltage.

Passive PFC uses a capacitive filter at the AC input to correct poor power factor. Passive PFC may be affected when environmental vibration occurs. Passive PFC requires that the AC input voltage be set manually. Passive PFC also does not use the full energy potential of the AC line. This level of PFC is becoming less common.


PC use is evolving. While still a dominant office tool, it is moving rapidly into high-performance gameplay and high-definition video display and transfer. With increased demands, it's advisable to upgrade the PSU in your desktop.

Upgrading a PSU on your desktop PC requires a little technical proficiency since you have to open the tower to remove the old one for replacement with a new one. Read user installation guide carefully. If you have any doubts of your capabilities, it's wise (and recommended) to find a reliable computer service technician.

While there have been various performance issues surrounding PSU standards, most current PSU models meet 80 PLUS and Active-PFC standards. This assures that if a PSU meets these criteria, it is likely to be dependable.

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