Power Supply: Quality vs Efficiency

Gentlemen of the Tek,

When building systems I have found that I spend the least amount of time investigating what power supply to get.  Does the quality of the power tend to increase with the efficiency, eg if the 80+ rating is better? 

Reviews never seem to discuss the quality of the power beyond reputation or brand name of capacitors etc.  In general or if I am overclocking, will my system be more stable because of a more efficient PSU or am I just saving money from better power efficiency?  Is power "smoothness" an actual thing, or is this largely taken care of by capacitors on the motherboard?

I have changed out many dead cheap PSU's for friends, but I've never had one die personally of about 6 machines since my K6-2 400Mhz box.  Am I not hard enough on my systems? Have you guys ever burnt a PSU?


have you ever heard of johnny guru? that guy tests the efficiency and quality. it requires both to make a good PSU. you want a storng PSU that can take some abuse so it lasts a long time, you want an efficient PSU so it Don't eat up too muhc electricity and you want it to supply clean stable smooth power for good over clocks.


OCN has list of good PSUs, some or most of whihc have been johhny guru approved.



EDIT: yes power smoothness is an actually thing this why johnny guru hooks them up to oscilloscopes and other electronic equipment while they are under load.


There is some correlation, in the way that it's not practically possible to make a powersupply of really cheap components that passes higher level of 80PLUS certification. Sample variance could still be significant and manufacturing precision could change over time, but the reliable brands don't tend to screw up too bad on this.

Overclocking to any higher level can certainly benefit from a better power supply, as anything that makes life easier on the motherboard raises the chances for kept stability. Though the quality of the board and that it is cooled well are still the bigger factors.

A better power supply can make the system parts last longer, and good power supplies themselves tend to last longer as well. Those factors make up for the higher initial cost more than saving a little bit of electricity does.

A failing powersupply of poor quality can take anything and everything with it as it dies. I had several harddrives die suddenly in the past, when a cheap PSU killed them before showing any other signs of acting up. Today any half serious PSU's have protection built into them and some motherboards can even warn of irregular power behaviour, but there's still some crap out there on the market made by what is essentially no-name manufacturers. Markups and fake brandings are not as common nowadays, but it still happens. Spending $20 extra in the low budget segment for power supplies can make a big difference. Be wary of system cases that are dirt cheap but still include a power supply. The chassis might still be worth the money, but the PSU is likely garbage.

Both are very important. When I really cheap out on the power supplies, I go with Logisys. They seem to have good PSU's at a very low cost. I have one in my server, been running pretty decent for about 3 years now. Never cheap out on the power supply unless you go with a logysis

the last cheap logysis i bought literally caught fire a the other week. they are probably some of the the worst PSUs money can buy. i'm fairly sure they are so light because they omit the safety circuits/features.

Some do catch fire. Which model did you get?