Best 100x PSUs in Efficiency @ Light & Super-Light Loads – Hardware Busters

This article will showcase the top 100 PSUs in Efficiency under light and super-light loads. With electricity prices rising, more people are becoming concerned about the efficiency of their PC systems, which is primarily defined by the power supply unit (PSU) they use. Several years ago, most PSUs sold were Bronze-certified in efficiency, meaning they weren’t particularly efficient; however, this changed once the cost of Gold-certified PSUs dropped notably. Currently, mostly Gold PSUs are preferred, but there are also significant markets, such as the Brazilian one, where Bronze PSUs are still preferred due to their affordable price tags.

Since most PC systems spend their time idle or under load, I will show you the most efficient PSUs at these load levels in today’s article. The notion that strong PSUs are not efficient at light loads no longer applies for quite some time now. To put it gently, this is an urban myth, as all modern platforms can operate in “burst mode,” which reduces power consumption by allowing the converter to operate for a predetermined time only, rather than constantly. You can read this article if you have an electronics background and want to learn more about “burst mode” and its side effects on the PSU’s performance, which include high ripple at light loads and increased EMI. This is why some brands send their products to certification agencies with burst-mode enabled, while for standard production, they shut it off. This is a significant fraud, in my opinion, as buyers believe that the PSUs they purchased are highly efficient at light loads, whereas they are not.

Intel is also pushing hard for more efficient PSUs, especially at light loads, through its ATX specifications on power supply design. The fact is that Intel had to back off slightly on the super-light load requirements, apparently because the PSU manufacturers complained about the strict requirements.

So, while in the ATX v3.1 spec for multi-12V rail PSUs, the following applies:

The previous ATX v2.53 spec included the following:

Typically, all ATX v3.x compliant power supplies should have an efficiency of at least 70% at a 2% load. However, the requirement is now 60%, and 70% is the recommended (non-mandatory) level. So far, most Gold efficiency and above PSUs I evaluated don’t have a problem exceeding 70% with a 2% load (or 10W for PSUs <500W max power and lower).

For the 20-80W average efficiency results, I won’t use Wattage categories, but I will provide the 100 most efficient Power Supplies. To avoid confusion, I will also apply this approach to the 2% load or 10W for PSUs with a capacity lower than 500W.

To assess the overall efficiency and performance, refer to my article on the Best ATX v3.x PSUs.

I will put some affiliate links for the products listed in the graphs. You don’t pay more using these affiliate links, but you help us keep this site alive and kicking! We also have a Patreon page, should you want to support us.

Although the PSUs shown in this article won’t be confined to ATX v3.x compliant only, if you have any questions about ATX v3.x PSUs, the following article contains everything you need to know:

Will my ATX v3.0 PSU or my GPU be compatible with 12V-2×6? Do I need a new cable/PSU/GPU? Everything you need to know!