When building a gaming rig, overprovisioning is never a bad idea. That being said, you can get away with cheaper power supplies if you’re putting together a budget build or breathing new life into an old one. Our best 550W PSU picks are an excellent place to start, so check them out and grab the one whose price, performance, or features you find most appealing.
Super Flower Leadex III Gold 550W
Form factor: ATX12V | Dimensions: 150 x 85 x 160mm | Efficiency: 80+ Gold | Fan diameter: 130mm | Modular: Yes | Rail power: 100W 20 A for 3.3 & 5V, 550W 45.8A for 12V, 15W 3A for 5VSB
- Excellent energy efficiency and low ripple
- Cool & quiet
While other manufacturers on our list produce various components, Super Flower focuses entirely on PSUs. No wonder the Leadex III Gold is our pick for the best 550W power supply. It’s completely modular, highly efficient, and the quietest fan-cooled component in your PC by a wide margin.
There’s also an RGB version, but we went with the regular version instead. It’s already expensive, and you’ll likely never see the RGB if your case has a PSU shroud.
The Leadex III gold uses quality components and comes with a decent cable contingent. Spacing on the Molex cables could be wider, but you won’t likely be connecting too many components through those.
Performance-wise, the power supply lives up to its ranking. All rails except 5VSB have minuscule load fluctuations, and the supply handles wall power interruptions well.
The PSU maintains or exceeds a 90% efficiency befitting its 80+ Gold certificate on all but the lightest loads. The transient response on the 12V rail is comfortably below the 1% threshold, and the two other rails aren’t far off either. Ripple isn’t a concern since all rails test within 10% of their standard’s maximum.
The good news continues with noise and thermals. The Leadex III Gold uses a 130mm fan that needs to spin slower to achieve the same low temperatures a 120mm equivalent would. It generates less than 20dB while doing this under load, making it far less audible than your CPU cooler or graphics card.
EVGA 550 B5
Form factor: ATX12V | Dimensions: 150 x 86 x 150mm | Efficiency: 80+ Bronze | Fan diameter: 135mm | Modular: Yes | Rail power: 120W 24 A for 3.3 & 5V, 550W 45.8A for 12V, 15W 3A for 5VSB
- Performance a tier above claimed certification
- Modular and with long cables
- Excellent temperatures under load
- Would benefit from some changes to cable complement
550W PSUs are meant for budget builds, so not many people will want to spend as much as our winner costs on one. Going with the B5 from EVGA instead will save you a couple of Benjamins while introducing a few downgrades. It’s still not dirt cheap, but this is the best 550W PSU for the vast majority of buyers.
EVGA went with an all-black modular approach and a 150mm chassis that will fit inside any non-SFF case. Japanese capacitors are the innards’ main driving force, but EVGA didn’t use them throughout. The cable selection is good, although replacing one of the six SATA cables with a second EPS one would have been better. They’re all long enough to comfortably build inside large cases, though.
The B5 might be certified as 80+ Bronze, but testing suggests consistent 80+ Silver performance. 12V voltage regulation is excellent, with only 0.1V drops at max load. Efficiency across working loads hovers above 87%, hence our certification bump.
The PSU is even more efficient than our winner while idling, which you might notice in your yearly power bill. Ripple suppression still falls well under ATX12V 2’s safety guidelines, but it’s more lax than on the Leadex III Gold.
EVGA went with a large 135mm fan that keeps the B5 in the low 40s at maximum output. Approaching the 550W mark sees the fan ramp up in speed & noise, competing with other fan-cooled components. Rather than masking the noise with a headset, you should consider a more powerful unit in that case anyway.
Corsair CX550F RGB
Form factor: ATX12V | Dimensions: 150 x 85 x 140mm | Efficiency: 80+ Bronze | Fan diameter: 120mm | Modular: Yes | Rail power: 120W 20 A for 3.3 & 5V, 550W 45.8A for 12V, 15W 3A for 5VSB
- Decent performance and build quality
- Cool and reasonably quiet operation
- Attractive RGB lighting
- 12V ripple suppression and voltage regulation could be better
Some people want RGB everything, and Corsair is the go-to vendor when it comes to light-up power supplies. Pretty colors might be a factor, but the CX550F gets our vote for the best 550W PSU with RGB since it’s efficient and passes most tests with flying colors.
Corsair offers the CX550F in either black or white. The latter comes with all-white cables too, making it ideal for the brightest enclosures. You may control the lighting if you have the Commander unit, through supportive motherboards, or via iCUE. As expected from Corsair, it’s vibrant and capable of dazzling with an array of cool effects.
More importantly, here we have another 80+ Bronze PSU that punches above its cert level. Its efficiency sits between 86 and 87% throughout all but idle-level wattage levels. This helps lower temperatures and improve component longevity. Not that the CX550F should have problems with the latter since Corsair didn’t cheap out on its entry-level PSU.
The PSU’s transient response is decent, especially on the 12V rail. However, other factors need improving. Voltage regulation is paramount for system stability, and the CX550F RGB’s 12V rail exceeds the 1% difference we’d like to see. The same rail’s 12V ripple protection is also mediocre. Ripple reaches more than 40mV at times – far below the 120mV limit but considerably worse than our first two candidates.
Even so, the CX550F RGB remains in the running thanks to low load temperatures and a reasonable 30dB noise ceiling. Both are noteworthy, given the smaller fan. Unlike EVGA and Super Flower, Corsair didn’t include a fan stop, though.
Asus TUF Gaming 550W Bronze
Form factor: ATX12V | Dimensions: 150 x 85 x 150mm | Efficiency: 80+ Bronze | Fan diameter: 135mm | Modular: No | Rail power: 120W 25A for 3.3V, 20A for 5V, 550W 45.8A for 12V, 15W 3A for 5VSB
- Long and varied cables
- Quiet operation
- Consistently hits advertised efficiency numbers
- Mediocre hold-up times, inrush current, and transient response
Our newest candidate for the best 550W PSU comes from ASUS. It might have a generic name that fits with the PC giant’s more affordable product line, but that doesn’t mean you should pass this power supply up. It’s attractively priced, easy to build with, and specced-out to handle any PC its wattage limits support.
ASUS keeps costs down by going the fixed cable route, but we don’t see it as a shortcoming. Cable variety is adequate, and we love how the EPS cable is! That ought to make building easier even if the appropriate motherboard header is far.
The TUF Gaming faithfully sticks to its efficiency certification most of the time, even dropping slightly below 85% when pushed past 100% load. Most rails have tight voltage regulation regardless of power consumption. The most important 12V one ends up at the wrong end of the 1% threshold, though.
ASUS employed a new architecture but used some less-than-stellar caps. You can see it in areas like hold-up times and inrush current readings, which are respectively lower and higher than we’d have liked.
Transient response is so-so, meaning the PSU struggles to maintain appropriate voltages more than others when tackling rapid changes in power requirement. Its ripple protection is better than Corsair’s, but this is another area that ASUS should work on.
We have no complaints about noise or thermals. The 135mm double-bearing fan is among the quietest on the list, and the PSU doesn’t get too hot when other components demand its full cooperation.
MSI MAG A550BN
Form factor: ATX12V | Dimensions: 150 x 86 x 140mm | Efficiency: 80+ Bronze | Fan diameter: 120mm | Modular: No | Rail power: 110W 20A for 3.3 & 5V, 546W 45.5A for 12V, 15W 3A for 5VSB
- Good value for the money
- Above-average efficiency
- Quiet operation
- High inrush current and low hold-up times
MSI makes our most affordable recommendation, the MAG A550BN. A few factors keep it from becoming the best 550W power supply. Still, excellent efficiency and a fine choice of components will cause many to pick it over others for their budget build.
The MAG A550BN is a fixed-cable, dark-gray PSU with a curtailed side to better fit inside smaller cases. It has all the cables you’ll need to get a mid-range system up and running with plenty of SATA and Molex left over.
We’re glad this is another unit whose certs don’t tell the whole story. While 80+ Bronze is a mostly accurate estimate, the A550BN reaches 89% efficiency at certain usage levels. Transient response is fine, except the 3.3V rail trails the rest at times.
High inrush current is a negative to consider if you frequently turn your PSU off & on physically. Users in parts of the world with unstable power grids might also want to take note of the A550BN’s sub-standard hold-up times.
Conversely, the fan keeps temperatures reasonable while remaining in the 30dB range, even when pushing system power via benchmarking or demanding games. The A550BN can handle abrupt load shifts reasonably well, although transient response could be better. Ripple protection is adequate if pushing into inefficient territory when the 12V rail is working at full capacity.