what makes a good psu good?

[Internet Swag]

Gonna start working at a pc store and I might get asked.

Id prefer a sentance that customers can understand

[jaffacakes]

Gonna start working at a pc store and I might get asked.

Id prefer a sentance that customers can understand

Quality build (depends on manufacturer), efficiency (80+ Bronze, Silver, Gold bla bla bla...) and that's about it. 

[PokémonTrainerFour]

Good quality components and trusted branding.

[sandals100]

http://www.pcworld.com/article/2025425/how-to-pick-the-best-pc-power-supply.html

 

http://rog.asus.com/59152012/news/what-makes-a-good-power-supply-toms-hardware-answers/

 

For more indepth answers.

[Akolyte]

High quality components, high trust brand and the efficiency rating.  

 

Do not be fooled by the effenciency rating.  Some Raidmax power supplies say they are 80+ Gold yet Raidmax power supplies are known to fail.  So, its more than just the effeciency rating. 

[Rorgash]

if it doesnt fry your components its good.

[Mooshi]

Lack of coil whine and not put together by child labour is a good start.

[Ren]

Higher quality transistors and capacitors, a decent fan, an ok price and a good rating. Bit more info below if you're interested.

Trans/Caps are (mostly) what make all of the difference when higher quality, keeping your power supply feeding your components with proper voltage/amperage is very important. This ties into the rating, but even an 80+ power supply can have decent internals.

Fan/cooling solution is a bit odd. I've not seen much innovation here nor do I know a lot about it. What is important is that they have a large enough fan within that has long-life bearings that'll stay lubricated/noise-free for the PSU you're using. Some 80+ rated PSUs might typically be replaced in 2-4 years*, while an 80+ Gold-rated PSU could last very very long, longer than you'd ever need it to in many scenarios, without being severely reduced in quality**.

O.K. pricing is a bit of a nuance since it will vary between brands heavily, but more importantly price is influenced across all brands by its rating and the cost of parts within. A PSU that uses high quality Caps/Transistors will likely cost more and be a higher rating. Another factor is capacity in watts but that should be obvious enough for most to understand.

Power efficiency rating.. Possibly the most encompassing information regarding power supplies of all. It's mostly related to hardware as I mentioned before. However, there's obviously bad power supplies that still manage to get decent certified ratings. This is where cost kicks in heavily (usually, anyway). In any case, it's easiest to say that a better rating will always mean a better power supply in some way or another. Look up 80+ power supply rating on wikipedia or something to find out more info.

*If you buy a 400W power supply, the chances are that you'll burn through it within 2-4 years either by it dying or you feeling uncomfortable having it be used anymore. Within that time, you might also see something better come out or simply want to add more hardware to your system than your PSU can power.

**Can't really say if I'm being accurate but you should know that it'll probably be used through your system's lifetime and you'd likely replace the power supply by the time you go for a new system. Lesser power supplies will degrade over time depending on their load sizes throughout the span of their lives, whereas many higher rated PSUs can live much longer closer to their max load. The importance of it all is really just to say that the higher the rating, the less likely the PSU will overvolt your system and fry your CPU/something plugged into PCI slots (as an example).

Total bonuses:

-Modular cables (sometimes drive up cost but honestly, it's becoming a standard to have semi/fully modular cables on PSUs)

-80+ GOLD rating. This is practically the sweetspot. It's not a ton better than 80+ Bronze but it is far cheaper than Plat/Titanium-rated PSUs while giving similar efficiency at various power loads. Save a few bucks by going with Bronze but after a certain point, you'll notice that they stop being made because it's difficult for an 80+ Bronze rating to exist on a decent 800W PSU. Manufacturers are trying to appeal to people who are spending hundreds/thousands of dollars on pc components that need quality over savings to keep these systems protected and efficient at such high loads. It's also easier for these people w/more money to spend the extra $30-$60+ on such hardware.

- Features/Software type stuff. Corsair has its PWM/silent operation technology for HX/RM/AX/AXi power supplies where the fan speed slows down if the PSU is using less than 60% of its max load. Others have similar features on their own PSUs, like Thermaltake's SMART brand, Cooler Master's new PSUs, all EVGA Nexus G/G2 power supplies, Be Quiet!'s PSUs,.. The list goes on. Corsair also has the digital power supply thing with AXi, so there's that too.

The names of brands I trust are Corsair, SeaSonic, SuperFlower, XFX, Cooler Master (new stuff), Thermaltake, ALL of EVGA's (amazing PSUs), Be Quiet!, and probably like 3 more I can't think of right this second but these are the big ones with proper manufacturing, good pricing for the most part, and some have excellent features.

[Lord Sparklebottom]

Build quality, noise, efficiency and (I think is important) cable quality.

[daemonowner]

There's more to a power supply than the brand on the box. Looking for power supplies from specific manufacturers like Seasonic or labelled with specific brands like Corsair is a start. Both Seasonic and Corsair have their lower end units, as everyone does. Seasonic does have a reputation for making good/excellent power supplies, but they're not the best on the market, and they're not the only you should consider. Corsair may offer good technically support, but they shouldn't be your only consideration either.

 

Efficiency, specifically 80Plus ratings: Not as important as people think. The amount a typical user will save over the course of several years will hardly justify the step up from a Bronze certified unit to a Gold certified unit, for example. @Faa may disagree, but I'm not convinced the heat output from the lost heat from inefficiency is very different either. Rather, 80Plus ratings should be a rough measure for the average consumer of the quality of the power supply. While there is more to making a good power supply than the components, a higher 80Plus rating is generally indicative of higher quality components like Japanese capacitors, a better design and layout, and better build quality like soldering. Also, as Mike said, above, 80Plus certification isn't always trustworthy. Sometimes companies will lie about 80Plus ratings, sometimes they will mislead you with labels that look like 80Plus labels but actually say "87%+ Certified", and sometimes the unit will be certified for Gold but can barely clear Bronze efficiency.

 

The actual performance:

Ripple suppression: Lower ripple is better. 120mv for the 12V rails and 50mv for the minor 3.3V and 5V rails are the ATX specs. Enthusiast grade power supplies should be looking for below 30mv on every rail. 60mv is pretty average. 10-20mv is very very good, and is seen in the likes of the AX1500i and EVGA G2 850W.

 

Voltage Regulation: 5% is the ATX spec for each rail. High quality units like the EVGA G2 750W will have below 1.5%. 

 

Efficiency: You should be looking for 80Plus Bronze minimum, even in the cheapest budget units. As technology advances, it becomes easier to make better and more efficient power supplies, and this is about where we're at now. Gold is pretty average for good units. Titanium is set to replace Platinum as the most balls-to-the-walls amazing and expensive certification. Despite certain people recommending nothing below Gold, the efficiency isn't the most important factor. You don't have to break your budget for several % better efficiency. High quality components and good performance are more important, and usually lead to higher efficiency anyway.

 

Other things:

Modular cabling: Many power supplies are semi-modular, meaning the most commonly used cables like the 20+4pin power and 4+4pin EPS CPU power cables are still non-modular (hardwired), while some PCIE connectors may be modular, and most or all molex and sata connectors are modular, meaning you can connect what you want. Semi-modularity is fine especially in high wattage power supplies, where you will be using these cables. Full-modularity means all cables including the main 24pin connectors are modular. Modularity is more expensive than non-modularity, which is why cheaper power supplies are non-modular. Full-modularity is also convenient for individually sleeving the cables to colour-match your build.

 

Black cables, good sleeving: Black cables are an inconvenience while assembling the power supply. The cables are usually colour-coded for ease of assembly and modification, but many people prefer full black cables. Enthusiasts usually look for good sleeving, which is more expensive and time consuming to do.

 

Semi-fanless modes: Some manufacturers and brands come up with fancy names for them, like EVGA's Eco-friendly mode. Essentially they either mean the fan won't turn on at low loads when not much heat will be produced, or you can flick a switch to enter the semi-fanless mode, which does the same thing. The end result is making your PC quieter at lower loads. Having good fans and being quiet is generally nice, with or without the fan going. Power supplies aren't usually the loudest component, and when gaming your GPU fans will likely be much louder and drown out the large PSU fan.

 

Build quality. Capacitors: Things you should look for in reviews are good quality capacitors (typically Japanese 105C rated capacitors) and good soldering quality.

 

Price: It's nice when a power supply is priced well for what it is. What more can I say. Over time you get a feeling for which power supplies are better than whichever similar power supplies, and you can compare prices on common etailers like Newegg. PCPartPicker is your friend.

 

Software, as mentioned above. I believe power supply software will be a big thing in the future. Corsair's C-Link software is well-known, and well-known for not being particularly good. Better than most, but it needs more work. Even if most people won't care about PSU software, I think it will become a trend for a while.

 

At the top of this Subforum on JonnyGuru.com are a bunch of stickied pages you should browse. http://www.jonnyguru.com/forums/forumdisplay.php?f=3