5 years out of a PSU?

PhillyDee said:
It probably never outputted 480W to begin with :p.

Seriously though, they do lose a certain amount of efficiency over time, though I am damned if I can find the source of the article! My google-fu skills are weak.
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I'd be interested to see the article which said that they lose efficiency over time... as it's not mentioned at all here:

http://en.wikipedia.org/wiki/Switched-mode_power_supply

It is true that some electrolytic capacitors can and do lose their capacitance as the years go on, especially in hot environments, which may be why someone would think that the efficiency goes down... but usually once the capacitors start to die then the whole SMPS normally stops working altogether.
 
It's all about capacitor aging. Depending on the type of capacitor, the aging process is different - for example, most caps using a dialectric film suffer from breakdown of the dialectric material. The aging of the capacitors makes the circuit less efficient, thus producing a lower power output. Most of those PSU calculators include a capcitor aging option, although I am not sure what level (it is usually given as a percentage) is obtainable before the capacitor fails entirely.
 
i had the same psu frfom 2000-2006 and im sure those caps were much worse than modern solid caps which i imagine most psus use

btw no way is your system using 500watt they are just reccomending a 500watt psu
 
wilko49 said:
It's all about capacitor aging. Depending on the type of capacitor, the aging process is different - for example, most caps using a dialectric film suffer from breakdown of the dialectric material. The aging of the capacitors makes the circuit less efficient, thus producing a lower power output. Most of those PSU calculators include a capcitor aging option, although I am not sure what level (it is usually given as a percentage) is obtainable before the capacitor fails entirely.
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I'm guessing electrolytic capacitors tend to be affected the most by ageing? The only problem is that there's no real way of telling how well your capacitors have been affected by ageing unless you unsolder each one and measure them with an ESR meter... Usually the ESR goes up with age, and the capacitance decreases.

Some capacitors are built better than others also, for example Rifa PEH-169 caps are overfilled with electrolyte so they do not dry out, if you shake them you can hear the liquid sloshing around. These last very very well and also have a very low ESR meaning they will probably outlast whatever equipment they are being used in...

Still, it would be good to see exactly how much effect old capacitors have, but short of putting your PSU in a time machine it's not easy to see how much effect cap ageing has... I'd be surprised if it's more than a few % effecicency however...
 
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I've had a 430W Thermaltake running for the last 6 years. A number of factors affect this. On the downside I've seen basic ones (came with base units) go in 1-2 years.
 
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