So basically a small recap.
Those cheap power supplies have a few issues.
1. No power factor correction.
2. Very poor efficiency ... 75% or less at low loads like 50w, which is common these days with modern hardware, and around 78-80% at higher loads like 200-300w. In contrast, modern power supplies can be up to 94-96% efficient.
3. They are often NOT capable of reaching the advertised numbers on the label, like for example a 650w power supply will barely do 300-400 watts.
Often they plain LIE on the label or add up the numbers incorrectly to trick people into thinking a power supply is capable of more than what it can do in reality.
4. They use very cheap electrolytic capacitors which will be subjected to lots of heat at high loads, and OVER TIME (months) they will degrade and cause voltage ripple to increase, which in turn causes VRMs on video cards and other components to work harder and in rare cases to even cause failures in video cards
I've personally had to replace the 5v standby capacitor on several such power supplies, because it failed - as the 5v standby circuit is always on, the capacitor is always hot due to hot diodes being right by the capacitor and fan not spinning while the pc is powered off
5. They use very poor quality sleeve bearing fans with little lubrication, and these fans often seize after around 1-2 years of operation (depending on how many hours the psu is used)
As a side comment ... looking at that Youtube video with the Kratos power supply... ripple voltages of 50mV and up while technically within ATX standard, are really bad for video cards, it's proven a lot of modern video cards don't like more than 20-30mV of ripple and the vrms sometimes overheat and the cards can't sustain auto boost / turbo modes, and all this results in worse video card performance. To a lesser degree, same applies to CPU vrms.
These old designs also don't meet the standards required for very low power sleep states, and often are unstable at ultra low loads like under 5w or so ... and often instead of reliable sleep modes, the computers just lock or shut down because processor can't wake up from sleep because the power supply can't handle it.
They also don't meet the latest EU regulations about "vampire power", which require less than 0.5w of power consumption in standby, and something like >70% efficiency for the 5v standby circuit
You as a seller may sell these CHEAP power supplies and they may work when you install them, fresh out of the box, and most people these days have computers that barely hit 300 watts of power consumption, so you're just lucky they don't blow up or cause issues, but you're not there 1-2 years after the sale when fans die or electrolytic capacitors go bad, or when the primary transistors blow up, and you can always blame the lack of line conditioners and not give that person another power supply when they complain.
Get in the last decade and accept the fact that modern designs can achieve high efficiencies of over 90%, so when a person plays game on the computer the power supply no longer has to struggle to dissipate 50+ watts in the form of heat.
Modern power supplies even come with 5-7 years of warranty, some even come with 10-12 years. What does that say to you, when you compare it to the 1 year of debatable warranty of those cheap power supplies?
I paid a bit more quite a few years ago and bought a Seasonic X-650 power supply ... still working like on the first day and I'll probably use it for another decade. Compare the internal design with your shitty old designs :
http://www.jonnyguru.com/blog/2013/02/04/seasonic-x-650-km3-650w-power-supply/5/Does this look "crowded" to you ?
Home
Help
Search
Login
Register
