Power Supply Ratings, Exactly What do They Mean?
Choosing the right Power Supply Unit (PSU) for your needs can be a tricky task, especially when there are so many reputable brands offering great PSUs at affordable price points. It isn't just price and brand that makes choosing a PSU difficult though, manufacturers have recently (since around 2004 to be more precise) started to add an 80 Plus rating to their power supply's to make the decision even harder.
The 80 Plus rating system is used to rate a computer's power supply and is based on reliability and efficiency. It's a system that was put in place over ten years ago to outline the variety of different classed PSUs clearly.
Whilst the 80 Plus system may look quite technical; it's actually quite simple to understand once explained. Let's take a look at the system and the different certification levels.
Power Supply Ratings
|% of Rated Load||10%||20%||50%||100%|
|80 PLUS (otherwise known as 80+ White)||--||80%||80%||80% / PFC .90|
|80 PLUS Bronze||--||82%||85% / PFC .90||82%|
|80 PLUS Silver||--||85%||88% / PFC .90||85%|
|80 PLUS Gold||--||87%||90% / PFC .90||87%|
|80 PLUS Platinum||--||90%||92% / PFC .95||89%|
|80 PLUS Titanium||90%||92% / PFC .95||94%||90%|
As you can see from the table above, there are six clear power supply ratings. They start at 80 Plus Standard (otherwise known as 80+ white) and go up to 80 Plus Titanium. In today's market, you will hardly ever see a PSU labeled with the 80 Plus Standard rating because they simply don't provide high enough levels of reliability or efficiency anymore. Most of the higher end PSUs showcase the 80 Plus Gold certification and are, as you can probably imagine, quite a bit more expensive.
Manufacturers have seemingly ditched the unpopular 80 Plus Silver rating as they feel there's no need to have a rating step between 80 Plus Bronze and 80 Plus Gold. As you can see from the chart above, distinctions between the different certification levels are quite low, so why bother providing such a small improvement on the 80 Plus Bronze?
We saw the market value of the 80 Plus Platinum rated PSUs drop significantly when Titanium's hit shelves. Great news for anyone looking to buy a platinum rated PSU. With the Titanium came the fourth PSU efficiency measurement, 10% rated load. You can see this in the table below:
|% of Rated Load||10%||20%||50%||100%|
|80 PLUS (otherwise known as 80+ White)||--||82%||85% / PFC .90||82%|
|80 PLUS Bronze||--||85%||88% / PFC .90||85%|
|80 PLUS Silver||--||87%||90% / PFC .90||87%|
|80 PLUS Gold||--||90%||92% / PFC .90||89%|
|80 PLUS Platinum||--||92%||94% / PFC .90||90%|
|80 PLUS Titanium||90%||94% / PFC .95||96%||94%|
What Does 80 Plus Actually Mean?
Every power supply that is certified by the 80 Plus standard will supply at least 80 percent power efficiency at 20, 50, and 100 percent load. Additionally, each power supply rating must show a power factor of at least 0.9 at a 50 percent load.
The power factor for those wondering is another measure of efficiency that captures the ratio of power going into the power supply unit itself versus the power going out into your build.
A good way of understanding the 80 Plus Standard efficiency side of things is to give an example of it. So, for example; if a power supply draws 375W from the wall socket, and provides your computer with 300W of power, the efficiency of this PSU is 80%.
This can be calculated by dividing 300 by 375, which equals 0.8, or in our case, 80%.
Which Power Supply Should You Buy?
Well, that answer all depends on you and what you actually plan on using your PC for. The choice comes down to a few main factors: How silent do you want your build to be, how much money do you plan on spending, and how safe do you want your PC to be.
Power supply's that have higher efficiency levels produce less heat. This, in turn, keeps them quieter as the fan is less likely to be activated over the course of using it. For this and a bunch of other build quality reasons, higher efficiency PSUs come labeled with a much higher price tag.
A factor that yields a lower priority level is the safety level of the PSU. Now, don't get me wrong; having an 80 Plus Bronze standard PSU isn't dangerous in the slightest. However, it isn't as safe as the higher tier rated PSUs. This is something you may or may not want to take into consideration, but it is a factor regardless.
Price is ultimately one of the main factors as well. As we mentioned above, if you're looking at a higher rated PSU, then you should prepare to fork out for the premium features they come with.
Hopefully, that was easy to follow and now gives you a better understanding of what the power supply rating system means for your PSU.
Ultimately, picking which one is best suited to your needs comes down to you, and you alone. However, hopefully, after reading this article, you will have a better gauge on which one to pick going forward.
If you have any questions regarding power supplies, then feel free to drop us a comment in the section below!