2 replies to this topic

[Mul.]

FSW PSU Guide

Index
What is a PSU?
What Determines a good PSU?
What Happens When A PSU Fails
Trusted PSU Vendor List
Current PSU's of Choice

What is a PSU?

PSU. Power Supply Unit. A Cube/Cuboid shaped transformer mounted inside your case, towards the rear. Electricity supplied to your home is AC (Alternating Current). This is no good for a computer and as a result a transformer is used to convert Alternating Current to Direct Current. The Voltage is also stepped down from 110V/240V to split Voltage rails inside the computer of +3.3V, +5V, +12V, which in turn power certain components within the system. Without any argument it's the heart of a Computer.

Some data you need to understand.

Power- Energy transferred per unit time. Power Supplies are advertised by the amount of Power it can deliver to the components. Units in Watts (W)

Voltage- Energy transferred per charge carrier. You may need to understand the importance of the 3.3V, 5V and 12V rails.

Current- The flow of electricity to components. Units in Amperes (A)

Efficiency- ((Power Drawn From Mains) / (Power Effectively Used)) * 100%
where > 75% is ideal.

Anyway, that's more than enough background information for now. Lets move on.

Edited by Mul., 16 November 2007 - 06:18 PM.

[Mul.]

What Determines a good PSU?

In short. One that's less susceptible to failure. Let's expand on that. What are the traits of a PSU that's susceptible to failure?

- Low Quality Internal Components. Difficult to judge as a consumer but sub $40/£30 price tag should ring alarm bells.

- Low Efficiency. This is infact a consequence of the above factor. The Conservation of Energy Law states that within a closed system, Energy (Power) cannot be created nor destroyed but are transferred in different forms. No Transformer can be 100% efficient. Inevitably, while some energy is transferred effectively as Electric Energy, some is transferred as heat or possibly sound. The latter two forms of energy transfer is effectively wasted or useless. A good PSU will waste less energy while a poor PSU will waste more energy. A PSU with a poor efficiency will always have to work harder to deliver the same power to the system components and this in turn can lead to failure.

Example.

A given system required 400W under load to function. We'll use a hypothetical PSU with a 80% efficiency and another with a 65% efficiency.

The first PSU needs to draw 400 / 0.8 = 500W from the Power Socket/Mains.
The second PSU needs to draw 400 / 0.65 = 615W from the Power Socket/Mains.

This in turn actually makes your system more expensive to run in terms of Electricity Bills.

The above are factors that make PSU's more susceptible to failure.

Edited by Mul., 18 November 2007 - 09:28 AM.

[Mul.]

What Happens When A PSU Fails

Sometimes a PSU shows symptoms of imminent failure. This may include system lockups, unexpected system restarts but also unexpected shut downs. More than often this occurs when the system is fully loaded, running a game or other intensive application. Eventually this can also happen when a system is just idling as a PSU continues to deteriorate. On the other hand, PSU failures can be imminent as well. In short, when PSU's fail there is a risk of it producing a surge effect that can damage or destroy other components within the system. Quite often the Motherboard is the first victim, followed by CPU, RAM and Disk Drives. This tends not to happen with well built PSU's.

Trusted PSU Vendor List

My honest advice would be not to choose any brands other than the ones mentioned below. There may be some brands that I've missed out but you cannot go wrong with this selection.

Akasa
Corsair
Enermax
Fortron Source (FSP Group)
OCZ
PC Power & Cooling
Seasonic
Tagan
Thermaltake (Toughpower Range Only)

MUST Avoid List

Aspire/Apevia
Hiper
Qtec
Raidmax

Current PSU's of Choice

Budget- FSP Group 450W ATX2.0 PSU
Performance – Seasonic S12 500W/Corsair HX 520W/OCZ GameXstream 600W
High Power Consumption (SLI/XFIRE + QUAD RIGS)- Seasonic S12 650W Energy Plus/ Corsair HX 620W / Tagan Dual Engine 800W / Enermax Galaxy Range.

Finally a list of PSU Brands and Models that are 80 PLUS certified
http://www.80plus.or...su/manu_psu.htm

Edited by Mul., 16 December 2007 - 07:47 AM.