The Big Power Supply Guide - Notes
Collected here are some notes on power supplies that didn't warrant their own section, but were too important to leave out.
Yes, they're pretty. And removing unused cables can be easier than tucking them out of the way. But be careful. Part of the problem is inherent in the supplies being modular: adding another connection adds another source of resistance, another possible point of failure, and just one more thing to go wrong. These are nontrivial but (fortunately) not huge issues. The bigger part of the problem is that many of these supplies are absolute garbage. If you take junk and make it slightly worse, it's still junk. Many manufacturers use features like modularity as a way to sell otherwise inferior products. So if you are going to go this route, spend the money on a quality supply.
When shopping for a power supply, it's very tempting to look at nothing but the total power rating. After all, a 600 W power supply sounds a lot better than a 350 W power supply. But it may not be. For a couple of reasons. Firstly, the way that rating is derived is rather complex. And secondly, it's easy to lie about it. Thirdly, and most importantly, not all supplies are created equal. A good supply with a lower rating will often outperform a bad supply with a higher rating. That's why this guide was created; to help you get past the marketing and to the truth.
There are lots and lots of brands on the market. But not a lot of manufacturers. The fact is, a small number of factories put out hardware that is then given new markings and sold by a variety of companies. This isn't uncommon in computer hardware; memory, laptops, and other products follow similar models. Typically a brand will give one of these manufacturers the marching orders of what to build, and the manufacturer will do most or all of the real work. The brand may then package the supplies under the various names it owns (the FSP Group might mark a supply Fortron or Sparkle as suits its fancy, for instance) or hand it off to another company for further rebranding.
So the honest fact is that things are not always what they seem. You may have to go to some effort to determine who actually made your power supply.
This is particularly important to know if you buy from certain companies. You see, some companies rebrand supplies from several other companies. These may be built to wildly different specifications, and hence vary wildly in quality. Rosewill is a good example of this. Rosewill is Newegg's "house" brand. They remark supplies from dozens of companies, whatever is immediately available. So buying Rosewill is like a box of chocolates: you never know what you're gonna get.
There's an old saying that you buy power supplies (and, uh, banjos) "by the pound". The idea being, that heavier supplies (and banjos) are better supplies (and banjos). And it's a pretty good rule to follow. Quality power supplies use nice solid transformers and big heatsinks. That means using a lot of metal. Expensive metal. Heavy metal. And using more of that heavy metal in a supply makes the supply heavier.
For banjos the issue is the tone ring, which in quality banjos is made of heavy metals like brass.
You may notice that on the list of trusted supplies, the links all point to a few companies. Wherever possible we have tried to link Newegg, Chiefvalue, ZipZoomFly, or other vendors we have personal experience with. In other cases, we relied on the testimonials of others.
A laundry list of well-respected models was made from several sources. This was then cut down to those offering the best value within their particular segment. And then a bit of quick comparison shopping.
Many sources contributed to this guide, and it would be impractical to acknowledge all of them. Some of the highlights:
- [H]ardOCP's power supply forum is a wealth of information. Particularly interesting are the recommended power supply thread and list of PSUs to avoid.
- jonnyGURU (often seen on [H]ardOCP) has both reviews and a forum.
- Extreme Overclocking has a fairly technical article on power supplies.
- Dan's Data is usually right about just about everything, including power factor correction.
- Xbit has published two helpful articles on video card power use.
- We continue to be indebted to Justin, who helped beta-test the new layout used for this guide.