Another dead power supply

[Peter]

On Mon, 5 Dec 2005, Mike Newman wrote:

> On 12/5/05, Lennart Sorensen <lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org> wrote:
>> I used to spend $200 to $300 on PC Power & Cooling TurboCool 300s, but
>> now I use Enermax or Antec for a lot less money.
> I got an Enermax a year ago and it's worked flawlessly until about two
> weeks ago. It just coughed and suffered permadeath this weekend.
> I loved that the fan kept running for a couple of minutes after
> shutdown (why doesn't every component do that?), but for the price I
> really expected more than a year of service. Just my $0.02.

You could introduce some metrics using f.ex. (power * known_life)/price, 
otherwise it's comparing apples with prunes. A brand name PSU would have 
to run 4 times longer than a no name cheap one on account of the price 
difference alone. That is equivalent to roughly being twice as large or 
running 20 degrees (Celsius) cooler (imagine the fans this requires, 
given standard PSU size).

This is very roughly estimated, based on the fact that electronic 
component life (esp. capacitors) halves with each 10 degree C 
temperature rise. To put this into perspective, 4khours 105degC caps 
(this is very high quality for todays standards) run at 55 degC will 
last about 14 years. Put in 2k hours caps (run of the mill) and run them 
at 65 degC and they will last at most 3.5 years. Put in standard 85degC 
caps with 2k hours and it will last just under two years at 55 degC. The 
actual life of the unit is influenced by all of its parts, so it will 
last less than calculated like this.

So imho barring any drastic departures from the laws of physics or 
severely flawed design, temperature is the most important factor in PSU 
life.

Of course a surge filter is a very good investment if the PSUs are to 
die of old age ONLY.

Peter
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