Anything goes, but… can power supply cause hardware down – page 2 gas density at stp

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Older PSU designs would use iron core based step down transformers that were expensive and bulky. Iron core design units had poor Power factor(PF) and load requirements that did waste energy. Each rail required separate circuit controls for each winding of the transformer.

Most modern PSU are ferrite core based torroid transformer instead of a iron core step down type which can be costly and bulky. Efficiency for a switched mode supply is the ability to provide required power rails with minimal lose thus better Power Factor(PF). Modern designs are switching power supplies to produce the required voltage and current needs for each rail specification.

PSU is fair representation for modern switch mode units that are widely used today in home and industrial supplies. Newer CPU designs utilize the +3.3 VDC rail instead of the +5 VDC. But the systems still require a +5 VDC along with a +12 VDC rail which supplies for the motor needs of the system. -12 VDC requirements are minimal today since serial communication via RS-232 are rarely used.

Quote: Power rating The overall power draw on a PSU is limited by the fact that all of the supply rails come through one transformer and any of its primary side circuitry, like switching components. Total power requirements for a personal computer may range from 250 W to more than 1000 W for a high-performance computer with multiple graphics cards. Personal computers without especially high performing CPUs or graphics cards usually require 300 to 500 W. [12] Power supplies are designed around 40% greater than the calculated system power consumption. This protects against system performance degradation, and against power supply overloading. Power supplies label their total power output, and label how this is determined by the electrical current limits for each of the voltages supplied. Some power supplies have no-overload protection.

The system power consumption is a sum of the power ratings for all of the components of the computer system that draw on the power supply. Some graphics cards (especially multiole cards) and large groups of hard drives can place very heavy demands on the 12v lines of the PSU, and for these loads, the PSU’s 12 V rating is crucial. The total 12 V rating on the power supply must be higher than the current required by such devices so that the PSU can fully serve the system when its other 12 V system components are taken into account. The manufacturers of these computer system components, especially graphics cards, tend to over-rate their power requirements, to minimize support issues due to too low of a power supply.

Healthy periods often relate to how much the PS weighs. A 300W rated PS that weighs half what another 300W rated PS weighs likely can be expected to last little beyond its warranty period, if that long, whereas the heavier one likely will last as long or longer than RAM, CPU and motherboard. If a power supply is included at no extra cost with a $29US case, it’s likely super lightweight garbage good for use at most a few hours per week and beyond that little more than causing premature motherboard, HD or CPU failure – if it lasts long enough.

I’ve been building PCs for going on 3 decades, but only as tools, not toys for playing games, and with GPUs that work reliably without active cooling or a dedicated power connector. The highest rated PS I’ve ever bought is 500W, only once, with most rated between 300W & 450W. For most PCs I’ve built, 500W is at least double what the components require. My 3 newest Dells came with 235W rated PSes. Intel Mac Minis commonly ship with PSes in the 80W to 110W range. Overbuying PS rating is like equipping a 2500 lb convertible with a 7 litre V12 – inefficient loaded to a modest fraction of capability.

In sum, add up what the components require, then shop accordingly, taking potential expansion, product weight and brand reputation into serious consideration. If you can, conserve the environment by buying an 80 Plus or better rated model. And if you want it to last, either keep it clean, or clean it regularly.