Choosing the right PSU or Power Supply Unit can be overwhelming. After all, the power supply is literally what makes your PC run, so you can’t afford to take it for granted. Power supply ratings can also be confusing, and you might end up wasting money on an expensive power supply unit at no additional benefit if you’re not sure what’s what.
In this article, we explain what a power supply is and what determines its efficiency. Before you begin, it’s advisable to figure out exactly how much power you need. For the sake of simplicity, we’ll be using the terms ‘power supply’ and ‘power supply unit’ interchangeably.
What is a Power Supply?
Electric current can be of two types: direct and alternating. The electricity that a wall socket provides is alternating current or AC. However, most modern devices are designed to run on direct current or DC.
This means that the direct electricity from a socket will be too powerful (and thus damaging) for your PC. That’s where your power supply comes in. A power supply converts AC to DC, but at a safe level. Power supplies can be either linear (less noise, more heat) or switched-mode (less heat, more noise).
What is Power Supply Efficiency?
Now that you know what a power supply does, its efficiency is simply a ratio that determines how well it does this job. So the better a power supply is at converting input electricity to output electricity for a device (and with minimum waste), the more efficient it is.
Power supply efficiency ratings are this ratio in percentage form. For instance, let’s say a device needs 360W to run. Its power supply takes 450W from the socket, converts it to DC with some expected loss, and gives the device the 360W it needs. This power supply would have a rating of 80% (360/450).
The Dangers of Choosing the Wrong Power Supply
The extra energy lost in conversion becomes heat or field waste. Both can be very damaging to your computer. If your power supply doesn’t provide reliable or clean electricity, your PC could become inexplicably unstable.
This instability, combined with excess heat leads to random resets and shutdowns as well as freezes. On top of that, field waste can damage your GPU or motherboard.
How Do Power Supply Efficiency Ratings Work?
The 80 plus certification is something you’ve probably come across by now. This is also a power supply efficiency rating, and it simply means that the PSU is at least 80 percent efficient at different workloads (which could be 20, 50, and 100 percent).
However, most 80 plus power supplies are most efficient at 50 percent workloads (which we call the peak), as compared to very high or low workloads. The benefits of using an 80 plus power supply include lower electricity bills (from saving energy) and greater system reliability.
Since 80 plus power supplies have different models, the extent of these benefits can vary. You can also update to a higher model if you’re already using an 80 Plus PSU.
80 Plus Power Supply Efficiency Ratings Options
Before 80 Plus, power supply was measured in Watts only, so this gave users an additional variable to measure performance. Now 80 Plus is the typical power supply efficiency rating. Efficiency increases with each newer model, and naturally, so does cost.
These models are listed here in order, from least to most efficient, with a quick look at how well they work at different workloads.
80 Plus: The Original
This is the oldest model and the one you’re least likely to be able to find on the market today. 80 Plus power supplies work at a simple 80 percent efficiency at all the three milestone loads (20, 50, and 100 percent).
80 Plus: Bronze
The Bronze model is a pretty good budget-friendly option, despite working better than its predecessor. The 80 Plus Bronze power supply works at an efficiency of 82 percent at the extreme workloads (20 and 100 percent) but goes to 85 percent easily at its peak workload (50 percent).
80 Plus: Silver
The Silver model hasn’t been that popular because people either prefer the one after or before it. Even though 80 Plus Silver power supply works at 85 percent efficiency at the extreme workloads and 88 percent at its peak, most users feel that its price isn’t a good enough bargain, especially compared to the Gold model.
80 Plus: Gold
80 Plus Gold is more of a premium option, but it does have a pretty good efficiency-per-dollar rate. The Gold model works at 87 percent efficiency at extreme workloads and 90 percent at its peak.
80 Plus: Platinum
The prices for platinum power supplies have fallen since the latest (Titanium) model was introduced, so you might get a good bargain for this. 80 Plus Platinum works at an efficiency of 90, 92, and 89 percent at workloads of 20, 50, and 100 percent respectively.
80 Plus: Titanium
80 Plus Titanium is the only model whose efficiency increases as workload increases. So for the three checkpoints, it works at an efficiency of 90, 92, and 94 percent! Given these specs, the Titanium model is obviously very expensive.
Are The Pricier Models Worth It?
When it comes saving money on your electricity bill, that will happen with an 80 Plus model regardless of which one you choose. But the model you choose should depend on the amount of power you use. A good way to figure that out is by testing your power supply.
If you don’t need very high performance, then you can get a generic power supply rather than an 80 Plus. Lower versions of 80 Plus aren’t as widely available, and most generic PSUs still work at about 77 percent efficiency.
Remember, you can’t save on power you aren’t using. If your power supply has high specs that you don’t need, you will waste a lot of electricity in the form of heat and field waste. Similarly, if the specs aren’t high enough, your system won’t function well.