Are most Cheap & Nasty PSUs reliable, if you don't put a heavy load on them?

[VirtualLarry]

IOW, are they simply overspecced, or is there more to the issue with "cheap" PSUs?

What about cheap(er) ones, like the HEC models?

Interested in whatever cheapest PSUs I can get away with for some micro-ATX builds. Don't need 80plus, don't need PCI-E power cables. But PSU should not burn up when it is switched on for the first time, nor any time after that.

 

[Compman55]

I don;t know the answer to all of those questions, but what is very important is to enter the UL # online and find out who makes it, and if it has proper saftey devices.

Although almost any cheap psu will work just fine, but can burn your house down if they lack the proper saftey devices.

I never knew this, and did buy cheap cases back in the athlon XP days, and had have very little failures. Usually the fans have seized up and out came the smoke. Not so much the power supply's fault. These still made it 3 yrs which was good enough.

 

[piasabird]

I think there is a list of power supplies on the Forum about brands of power supplies that are not recommended or are preferable. I work in a community college and we have several thousand computers. We have seen some Dell Computers whose power supplies that failed. You can take any brand of power supply and some of them will fail at some time. Part of this is caused by faulty parts from suppliers. Sometimes it is because some power supplies rated at say 350 watts or 500 watts cant actually deliver the number of watts they are rated at. If a company purchases power supplies that are barely rated enough watts to support all the hardware over a time span of 3-5 years.

Power supplies produce power at certain levels and if you chart this it will be a curve. The Power supplied will taper off in efficiency as you near the rated power level. So you don't want to exceed 75% of a power supply rated wattage. Then other problems are things like how much heat the CPU or Video card and RAM produce and how well the air circulation in the case gets rid of that hot air.

To me a power supply should not create excessive heat and it should also run very quietly. Heat is what kills components.

 

[zir_blazer]

Considering that computer shops used to put lame Power Supplies (The ones that comes in Kit with the Case) in their builds, and they didn't seem to go boom THAT often, you could say that they should be averagely reliable. This was even more true in the Pentium 4 Prescott era. However, quality control as you expect is bad, so you could get a functional unit and another that is faulty and dies very early. This random chance of getting a bad unit that could kill something else is the actual evil. Usually the worst quality component is the Fan, which becomes very noise as time goes.
Just for the peace of mind, I would go for a reputable brand. There were some 400W or so Antecs and Seasonics which are very recommended for budget builds.

 

[VirtualLarry]

I would never use a PSU that isn't UL-listed.

Apparently, these SeaSonics are also NOT UL-listed.
http://forums.anandtech.com/showthread.php?t=2377569

 

[zir_blazer]

I would still trust it, more than any other generic Power Supply. Why? Because logos are easily stamped. The generic Power Supply market is full of scams with units that got plenty of logos, yet on the website of the organizations that certifies them, there is no proof that they actually tested that unit (Viceversa may also apply, when a PSU gets approval after launching, early batches may be missing logos). So when you see a Cheap & Nasty PSU, you may actually want to get proof that it is certified, because certification usually cost money and generic manufacturers want to avoid that.
For me, the best certification is that a good Reviewer like Jonnyguru or the guys from Hardware Secrets dissamble it, tells you what components are in it, and load test it.

 

[Blastman]

Considering that computer shops used to put lame Power Supplies (The ones that comes in Kit with the Case) in their builds, and they didn't seem to go boom THAT often, you could say that they should be averagely reliable. This was even more true in the Pentium 4 Prescott era.

This.^

I've seen a fair amount of local computer builds in the last 15 years that used the cheap stamped metal PSU's that came with the cases for builds that businesses used. They generally seemed to hold up pretty well because they were not being stressed -- probably 150W max for PSU's rated 225-325W.

The thing that usually failed on these cheap psu's was the sleeve bearing fan which would start to seize up after about 4-5 years -- sometimes sooner. If the fan stopped spinning, the psu would heat up and die pretty quickly. Most computers prior to Core 2 series were ditched for something new before 4-5 years was up (it was a real upgrade treadmill) so it usually didn't matter much.

I used one of these cheap case/psu's for a secondary computer in the basement for years with a Celeron-T 1.0. It was 4 years old when I got the (used) case/psu and I used it for 6 years. Psu was still running when I threw it out. If the fan started making noise or would run slow and erratic, I would just take the psu apart and lube the fan, shove it back in, and things would be good to go.

One thing to consider is that people are keeping computers a lot longer than in the P4 and previous generation CPU years. My current i3 is still plenty fine for general use and even decent enough for most gaming (overclocked) and it is already 4 years old. A lot of Core 2 dual-cores are probably still in use and are pushing 6-7 years old. I can see my i3 still being used another 10 years unless the M/B gives out and it's not worth it to get a 1156 replacement.

If you want the psu to hold out more than 4 years, and not be taken out by a failing cheap sleeve bearing fan, you will might have to upgrade to a psu that has a higher quality ball bearing or hydrodynamic sleeve bearing fan.

 

[Torn Mind]

Reliability in the sense of having issues while the computer is on or issues with the computer turning on/off is very much an either/or proposition. For a group of bad PSUs, even the crappy ones have units that can last quite a while with no or very little noticeable effect to the user. I have one crappy unit that powered a P4 machine, and the only really strange instance was when I closed Firefox and the whole computer just basically booted up again. Well, and that it couldn't deliver enough power to a second HDD.

The thing with some of the cheapies is that while they might run, what they do while the run can be damaging to the computer. Voltages going out of spec or noise/ripple going out of spec can cause instability or damange to anything downstream from the PSU(mobo and everything attached to it).

Another flaw is that there are not protection circuits or other circuits that monitor potential deviations from proper operation of the unit.

Yet another flaw with some super cheap units is that when they do die, the PSU just destroys everything with it.

As far as cheapies go, the Corsair CX series, the Antec BP350, and some Sparkles are the primary units I would consider. Diabloteks, Raidmax, Coolmax, and Logisys are to be avoided. For HEC, I guess the 80 Plus Bronze units that go for cheap from time-to-time at Tigerdirect are okay since someone tests them, even though the 80 Plus cert has rather lax standards with regards to proper operation of the PSU since they test the unit at room temp.