To avoid constant repeating of the same texts, here is a sum of all the informations about how I evaluate the power supplies. This text will be constantly kept actual if there will be some changes in methodology or instruments used. ACtual article version: 1.21. The evaluation methodology is most likely one of the most complicated ever, on the other hand it should be able to recleft wide spectrum of parameters you can find in power supplies.

History

1.0: Corsair VS450; pilot evaluation

1.1: Zlatá cihla; lowering requirements for -12V rail

1.2: increasing the penalty for not meeting efficiency demands and increasign the penalty/reward for high-end segment units ripple

1.21: grappling the penalties/gains for (non)functional protections and for burning during testing

1.22: grappling the penalties/gains for (non)present saving technologies and wire thickness

The basics remain at all times: the power supply must deliver rated power and must deliver the power within ATX specification tolerance to even be evaluated, otherwise it is not and will get the FAILED sticker. But the numerical evulation itself is not self-redemptive, if the unit falls behind in several areas and excells in others, it may still get overall good evalutaion even if I would personally not recommend such unit.

Therefore it is vital to take the numerical result into account together with the verbal evaluation in the final thoughts section. It is also possible that the ATX specification itself will change through time with a technological progress, I personally expect the -12 V rail to drop of the standard in time. For the time being, all the expectations are set up so high that really good power supplies will get high score, everything else what falls behing in some way will get less.

I postulate three cathegories according to price per watt ratio

• low-end: do 1,49 CZK/W
• mainstream: 1,5–2,99 CZK/W
• high-end: 3→ CZK/W

There is different set of criterias being observed in each cathegory. That means you cannot directly compare power supplies from different cathegories as there are different criterias for them! Average values of these criterias are pre-set, for which the unit gets basic amount of points. If it differs to one or other side (worse/better), it looses/gains extra points. All these groups are than summerized and the result is our final score value. One of the basics of this system is, that there are no absolute, uncrossable barriers like minimum or maximum. That means, it can happen that some units get better score than apparent maximum (100 %), or worse than apparent minimum (0 %).

The pre-set criterias are:

• component quality (0–15)
• built quality (0–15)
• voltage regulation under combined load (0–10) and crossload (0–5, rated half)
• ripple under combined load (0–10) and crossload (0–5, rated half)
• efficiency (0–15)
• price-per-watt (0–15)
• others, e. g. some special functions, acessories, longer warranty etc. (0–10)

Some of the expected values are specified under this paragraph, the basic amount of points for each set is in the brackets. If a unit meets the requirements exactly, it gets score of 60 %.

Low-end

• components must be adequately chosen (minimum for rated power); input filtration in minimum configuration must be present; output filtratino coils and capacitors must be present; 18AWG wires at least for main connectors; over-power protection (10)
• soldering can contain small flaws, manual repairs are allowed without restrictions; electrical safety must be at least bare minimal; maximum 5 tiny solder balls allowed (and not easily movable) (10)
• voltage regulation up to maximum allowed by ATX (10)
• ripple up to maximum allowed by ATX (10)
• average efficiency at least 75 % (10)
• price at 80 % of the interval, that is 1,2 CZK /W (10)
• nothing (0)

Mainstream

• components must be adequately chosen (aprox. 30+ % overbuilt); input filtration in minimum configuration must be present; output filtration coils and capacitors must be present; quality capacitors at least on effortfull +5 V SB rail; 18AWG wires for all connectors; over-power, undervoltage and overvoltage protections (10)
• soldering can contain small flaws, only one manual repair is allowed; electrical safety must be at least average;  maximum 2 tiny solder balls allowed (and not easily movable)  (10)
• voltage regulation up to 3 % difference (-12 V up to 6 %) (10)
• ripple up to 60 % of the ATX specification interval (10)
• efficiency set by 80+ Bronze (@115 V) certificate (average is than taken for the evaluation) (10)
• price at +50 % of the interval, that is 2,25 CZK/W (10)
• sleeved cables for main connectors (Main ATX, ATX 12 V, PCIe) (0)

High-end

•  components must be adequately chosen (aprox. 80+ % overbuilt); input filtration in minimum configuration must be present with at least one extra saving technology (X-capacitor discharge IC, thermistor bypass etc.); output filtration coils and capacitors must be present; only quality capacitors allowed; thicker wires than 18AWG at least formain connectors, 18AWG for the rest; overpower (overcurrent), undervoltage and overvoltage protections; golden-plating at least on main connectors (10)
• soldering must be flawless, no manual repairs are allowed; electrical safety must be exceptional (drilling between primary and secondary, extra component and leg insulation etc.); no solder-ball allowed (10)
•  voltage regulation up to 2 % difference (-12 V up to 2 %) (10)
• ripple up to 40 % of the ATX specification interval (10)
• efficiency set by 80+ Gold (@115 V) certificate (average is than taken for the evaluation) (10)
• rice in exact half of the interval, that is 4,5 CZK/W (10)
• all cables sleeved, at least 3-year warranty (0)

Here are also some examples of the point evaluation, some of the areas are than more individual rather than exactly pre-set: