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What’s the Best Power Supply in 2021?

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Sure, it’s not as exciting as graphic card shopping, but a PSU is the heart of your PC. The last thing you want is an inefficient machine due to poor power, especially after spending all that cash on the best components.

Plus once it’s dying, you might not know until it’s too late. And you want to get the right one from the start, as replacing one later is a pain. Fortunately, we’ve ranked the best power supplies: overall, as well as for gaming, video editing and streaming, and budget options.

What Makes a Good Power Supply?


Wattage is obviously the most important part of a power supply, and the first decision you need to make is: how much do you need?

There are huge leaps in price the stronger you go, so you don’t want to get more than necessary. Plus, higher wattage PSUs will mean a higher electricity bill and tend to generate more heat and noise.

You need to add up your motherboard, GPU and PSU power requirements to make a total. Then add a bit extra for security, and in case you plan on updating other components to something more power-hungry later.

As a rough guide, 750W or less will definitely be enough for most people. For gamers, 850W should do just fine. Only the most extreme gamers and 3D renderers will need to go beyond this.

Fortunately, there are tons of calculators around to make this easy for you:

Ratings and protection

PSUs come with some great certifications, such as efficiency ratings that (e.g. 80 Plus Gold) and noise ratings (e.g. LAMBDA-A+).

These instantly tell you the quality of the PSU.

Decent PSUs should also have decent protection features, such as OCP (Over-Current Protection) and SCP (Short Circuit Protection) to ensure everything runs safe and smooth.

The warranty is another big one. Because PSUs are so important and should last for the long term, they often come with long warranties. A long warranty also shows you the confidence the manufacturer has in its own product. They wouldn’t give out 10-year warranties if they weren’t sure of a quality, long-lasting build.


Finally, you’re going to want to make sure the PSU is actually compatible with your system, or you’re going to have major buyer’s remorse once you’ve unboxed it.

Check what connectors the PSU has, and make sure you’ve got the cables to match, with the right power supply.

Size is another big one to watch. Check the physical dimensions of the PSU to make sure it will fit inside your case. Just because you’ve got an ATX case doesn’t mean an ATX PSU is guaranteed to fit.

How We Choose Power Supplies

Features and Performance

The above features give a good idea of quality, but to really compare one PSU against another, you’ve got to perform real-life testing. With power supplies, there’s a whole host of things you can measure, such as ripple measurements to measure ripple suppression, cross-load tests and infrared to measure temperature.

Sure, there’s an efficiency rating of 80 Plus Gold, but that only specifies a minimum. Testing can tell you exactly how efficient it is at different loads, compared to competitors.

The same goes for noise.


We always bear the user purpose in mind, instead of just going for the flagship PSUs. User purpose is crucial for PSU, as different activities will require different wattages. For example, barely anyone needs above an 850W supply, so why spend the money?

Noise is a major issue for some, especially if you’re spending long hours editing video or want to stream without noise interference.

Value for money

The price has to be reasonable and fit for purpose. And the most important question is, can you get more for your money elsewhere?

Best Power Supply In 2021


Tech Specs

  • Form factor: ATX
  • Capacity: 750W
  • Efficiency rating: 80 Plus Gold
  • Modularity: Full

750W is a very popular wattage that combines the capacity of high-end hardware with competitive prices. It will certainly be enough power for most. And Corsair’s popular RM series has produced a model that’s currently the best of the bunch. It’s fully modular, meaning no messy cables. It’s got an 80 Gold Plus efficiency rating with LAMBDA-A+ certification. And on top of that, it’s got a staggering 10-year warranty.

Compared to its predecessor, it’s 2cm shallower, has a second EPS connector, and more peripheral connectors, all of which is much more practical. The connectors include the popular 8 four-pin Molex connectors, though the distance between them is 10cm, which is a little tight.

It’s very well-built. There’s a 135mm fan with a rifle bearing and microcontroller, which reduces noise. The ATX, EPS, and PCIe cables also come with capacitors to help reduce ripple.

These worked well, as ripple suppression on all rails was top-notch.

The real beauty of this PSU is its volume; it’s so quiet!

It’s average noise level (between 30-32°C) is just 19dbA. One of its main competitors at this price point, Seasonic’s SSR-750FX 35, was almost double at 35dbA.

That’s over 1.5 times the noise since a 10dbA increase represents double the apparent volume to human ears.

Even more remarkably, Corsair’s model even achieves near-silence at full load or overloads. It was just 30dbA at full load at 46°C, compared to the Seasonic SSR0750PX which reached 45dbA.

Performance is similar to the Seasonic, but the noise levels just edge it in front.

Honorable Mentions

Another well-rounded modular performer with similar specs and price, but noisier.


Tech Specs

  • Form factor: ATX
  • Capacity: 450W
  • Efficiency rating: 80 Plus Gold
  • Modularity: None

It’s got an 80 plus Gold efficiency rating, which is impressive for the price. Even within this, it tested over 89% efficiency, better than most competitors.

It’s very quiet, with a LAMBDA-A++ certification, which again is surprising at this budget, and shocking since it doesn’t even have a semi-passive mode and a small 120mm fan.

This is due to its excellent build. This well-designed PSU has minimal energy losses, which keeps it at a low temperature, enabling the fan to spin slowly and remain quiet.

Even at 100% load and over 46°C, the noise was below 40dbA. Below this, the fan never spun at its maximum speed and spun at its lowest speed most of the time.

3 +12V rails deliver 450w combined, and the 5VSB rail can deliver up to 2.5A.

In terms of protection features, OPP is set high and short circuit protection is on all rails.

Every rail had excellent ripple suppression, though in this aspect the EVGA 450 B3 does edge ahead. The ATX cable has capacitors to help reduce ripple on the PSU’s outputs.

Load regulation was tight on all rails, beating other 450 models like the EVGA 450 B3 and Corsair CX450.

Overall performance beat other popular 450 models (Corsair, EVGA), and was only very slightly behind the Seasonic SSR-550X.

There are 2 PCIe connectors and 2 4-pin Molex connectors. The distance between connectors is a nice 15cm. The PCIe and EPS connectors are powered by dedicated rails.

A big downside is it’s not modular, which makes cable management a bit difficult, but you can’t expect too much at this price point. And Bitfenix has chosen to sacrifice in this area, rather than the actual components, a wise choice.

At least the PSU is very compact at just 150 x 87 x 140mm, making it easier to install.

The warranty is 5 years too, which is very decent.

The power might not be enough for some, but if you can swing 450w, this is definitely the best all-round choice.

Honorable Mentions: 

EVGA 500 B1 – another excellent budget option if you need slightly more power, but it only has an 80 Plus Bronze efficiency rating and isn’t as quiet.

BitFenix Whisper 450 M – a slightly more expensive version if you want a modular PSU.


Tech Specs

  • Form factor: ATX
  • Capacity: 850W
  • Efficiency rating: 80 Plus Gold
  • Modularity: Full

Another Corsair RM offering takes the lead for gaming, too, with a model with much more power than the 750x, but a similar great design and warranty.

Again its fully modular with 80 Plus Gold efficiency, and that 10-year warranty to reassure customers of Corsair’s confidence in the quality of its products.

Like the 750 model, there’s a 135mm rifle bearing fan. It’s 20mm shorter than its predecessor, meaning it’s more likely to fit into your build.

The +12V rail delivers the full capacity. The minor rails are too strong, with 150W maximum together, whilst the 5VSB rail has a maximum output of 3A.

Again there’s 2 EPS connectors, 6 PCIe ones, and lots of peripheral connectors, including 8 Molex connectors. Again though, there’s only 10cm distance between these, which is less than ideal.

The cables have decent length, though, and the ATX, EPS and PCIe cables include inline caps for improved ripple suppression. Ripple suppression overall is excellent.

Again, it wins in the noise arena; it’s one of the quietest 850W models out there. It’s got a LAMBDA-A+ noise rating, quite an achievement for an 850w power supply.

EVGA’s 850 G3 and Seasonic’s SSR-850FX are the main competition, and they don’t achieve the same noise rating (LAMBDA-S++).

The build is excellent. Despite being smaller than its predecessor, it’s even quieter and performs just as well. A microcontroller enables slower fan rotation, and there are different controllers on the primary and secondary sides.

Some would like to see an updated look, though, as this design has been around a while.

Honorable Mentions: 

EVGA SuperNOVA 850 G3 – similar performance, but more pricey.

Seasonic’s SSR-850FX – similar specs, but not as quiet.


Tech Specs

  • Form factor: ATX
  • Capacity: 650W
  • Efficiency rating: 80 Plus Gold
  • Modularity: Full

650W should be enough for video-editing at resolutions at 4K and above.

And this is one of the cheapest 650W 80 Gold Plus models you can buy. It’s truly excellent value, especially for video editors who have probably already spent a whole heap on both a high-performing CPU and GPU.

You’d think this would mean certain sacrifices in performance, but no; it’s overall performance is actually one of the best of the 650W 80 Gold Plus models, including Corsair and Seasonic.

And the Super Flower build is solid (Super Flower are one of the best in the biz), with top-of-the-game ripple suppression and very tight load regulation on all rails.

The +12V rail delivers all of the PSU’s capacity, the minor rails are perfectly capable, and the 5VSB rail can deliver a large 3A.

However, noise-wise, it has a LAMBDA-A- noise certification. This isn’t the best, but it certainly doesn’t mean it’s ‘noisy’. It has an average noise of 27.31dbA. For comparison, this is louder than Corsair’s similar models.

The problem is the 130mm HDB fan gets a bit overly aggressive, rotating faster than most at lower temperatures. 

There’s also only 1 EPS connector which may be an issue for some users, as well as 3 PCIe, 6 SATA and 4 Molex.

It’s fairly compact at 85 x 150 x 150mm and comes with a decent 7-year warranty.

Honorable Mentions: 

Corsair AX1000 – if you need top-end power for things like 3D rendering, this is the best 1000W option.


Tech Specs

  • Form factor: ATX
  • Capacity: 600W
  • Efficiency rating: 80 Plus Titanium
  • Modularity: Full

This PSU sets records in many ways.

The best streaming requires total silence, and that’s what you’ll get with this fanless PSU. It’s got the top Cybenetics noise rating of LAMBDA-A++, which promises silence.

Noise levels were always below 28dbA, which is basically a whisper. 

Passive-cooling CPUs are typically reserved for lower wattages, but the Seasonic SSR-600TL bucks this trend.

It’s outfitted with high-quality 105c Japanese capacitors

Not only that, but it’s also got the highest Cybernetics efficiency rating of 80 Plus Titanium. This means a 94+% efficiency level at 50% load, and 90% at 100% load.

However, testing by third parties has shown it to be even better at 96% at 50% load, and 93.5% at full load.

With both top efficiency and noise, this makes it one of the highest-quality PSUs around.

It’s fully modular of course, and also very compact at 170 x 150 x 86 mm. Perfect for a streamer’s build.

There are 3 heatsinks and the entire thing is vented to allow maximum airflow.

The +12V rail can handle a stellar 50A, and the 5VSB rail an average 2.5A. However, the minor rails can only deliver 100W combined, which is a little weak, but they aren’t used much.

Load regulation is very tight, beating all major 650w competitors overall.

In terms of protection features, OPP is good and there’s short circuit protection on all rails. It’s well-protected from voltage spikes and large inrush currents as well.

Ripple suppression is solid, helped by high-grade 105c Japanese capacitors throughout. In fact, KitGuru found this model’s ripple suppression to be in the top 2% of all models.

It includes 2 EPS connections, 4 PCIe connectors, a rarity on fanless models, 6 SATA, and 5 Molex. There’s less than 15cm between the peripheral connectors, which isn’t ideal, but it’s limited by its overall size.

It’s overall performance beat all other major 650w models except for its own, the Seasonic SSR-650TD, which isn’t fanless.

650W should allow you enough headroom for components for game streaming at 1080p and even 1440p.

The only downside is the higher price you pay for fanless.

But at least Seasonic puts its money where its mouth is with a record 12-year warranty.

Honorable Mentions: 

Seasonic SSR-650TD – if you’re not fussed about silent passive-cooling, this is another great option.


Tech Specs

  • Form factor: ATX
  • Capacity: 650W
  • Efficiency rating: 80 Plus Bronze
  • Modularity: Semi-modular

If you want to game on a budget, look no further than this solid Cooler Master series. It’s not the cheapest available, but sticking with a decent brand that’s safe and reliable is worth it when it comes to PSUs, especially if you’ve invested in a mid-range graphics card you plan to overclock.

It’s got 80 Plus Bronze efficiency and is a pretty impressive 86.6% at full load.

Compared to competitors, it really impresses with noise as well, which is a definite plus when spending long hours gaming.

Up to 15% load (i.e. around 100w), this model is silent. Up to 270W, it’s only 28dbA, which is just above a whisper. At 500W it’s around 33dbA. Max dbA is 34.9. So basically, it’s whisper-quiet up until around 500W.

This is due to the Silencio FP 120mm fan, which has an LDB (Loop Dynamic Bearing) design with low vibrations and an ultra-low current.

The design is a clean-looking black and the build is decent for the price point, with decent soldering quality and 85c capacitors. 

It’s semi-modular, with 2 PCIe connectors and 2 SATAs.

Temperatures are around 62°C at full load, which definitely can’t match the premium 750w models, but you get what you pay for.

The +12V rail can deliver 54A, which is definitely enough for a gamer’s graphic card. The minor rails can deliver 22A combined.

Ripple suppression is good, hitting 50mV on the +12V rail at full load.

And finally, it comes with a nice 5-year warranty.

Honorable Mentions: 

Cooler Master MasterWatt 750W – if you need more juice and have a bit more cash, Cooler Master also has a 750W in this series.

Which Power Supply Should I Buy?

Most users will be more than happy with the stellar Corsair RM750x, a great all-round performer with enough juice for everyone. It’s a high-quality fully-modular build with an 80 Plus Gold rating, and as a bonus, it is very quiet.

High-end gamers who need a bit more capacity for that power-hungry GPU should go for its big bro, the Corsair RM850x. Gamers on a budget can’t go wrong with the Cooler Master MasterWatt 650.

Most video editors and streamers can get away with slightly less power. The super silent Seasonic SSR-600TL is perfect for streamers, whilst the EVGA’s SuperNOVA 650 G3 is the strongest performer in its field, and one of the cheapest, suiting video editors.

Finally, those on a strict budget will be best off with Bitfenix BF450G, if they can get away with the lower wattage.

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