In our series of holiday buyer’s guides, here’s the latest update to our recommended power supplies list. All numbers in the text are updated to reflect pricing at the time of writing.
Now that you’ve picked out your CPU, it’s time to start picking out the rest of your system components. And perhaps the most humble but overlooked of these components is the power supply unit (PSU). Available in a wide range of sizes and power capacities, there are a number of great PSUs out there, but choosing between them can be a challenge. So today we’re bringing you our annual PC power supply guide, to help you sort figure out what the best options are, be it a low-wattage unit for a small form factor PC, or a hulking kilowatt unit for the most powerful PC.
|AnandTech PC Power Supply Recommendations: 2021
(Prices are Nov-29 or MSRP)
|Output Range||Value Option||Performance Option|
|Up to 450 Watts||EVGA 450 BR||$35||EVGA SuperNOVA 450 GM||$80|
|500-600 Watts||EVGA 510 BP||$40||Fractal Design Ion+ 2 560W||$111|
|650-800 Watts||be quiet! Pure Power 11 600W||$70||Seasonic FOCUS PX-750||$150|
|850-950 Watts||Corsair RM850x||$110||Seasonic PRIME TX-850||$200|
|1000+ Watts||EVGA Supernova 1000 G6||$150||Corsair HX1200||$240|
|Up to 450 Watts||EVGA SuperNOVA 450 GM||$80||Corsair SF450||$115|
|500+ Watts||Seasonic Focus SGX-650||$130||SilverStone SX800-LTI||$220|
When shopping for a PSU, it is very important to be aware of your system’s power consumption and to consider any planned upgrades. All current computer PSUs are designed to deliver optimal performance at (or almost at) half load. Conversely however, it is a common misconception that a more powerful PSU will be a better choice, as the power quality and efficiency of all modern PSUs dwindles at very low loads. This is especially true at the low-end of the loading curve, usually below 15% of the unit’s rated capacity, where efficiency outright plummets. In fact, only the 80Plus Titanium guidelines dictate a low-load standard, and that’s an efficiency requirement of 90% at 10% load. Therefore, the choice of a too powerful PSU will result in poorer performance, which can be significantly worse than what a properly-sized product at a fraction of the price would deliver.
Overall, we’ve split our recommendations into five main wattage categories with at least two units for each. One selection will be based on the maximum possible value (e.g. bang for the buck) and one will focus on the best overall performance.
Looking broadly at the market for power supplies, PSU technology has been a bit stale as of late, as manufacturers are struggling to meaningfully improve their designs without driving up their costs. As PSUs have become very efficient and are now employing advanced design topologies, any further upgrades rely heavily on materials science, such as employing relatively expensive Gallium Nitride-based parts. Short of that, there’s a practical limit to how much an existing design can be upgraded by using better parts without making it too expensive for a price-sensitive market, which is why PSU designs have been advancing very slowly over the past few years.
Ultimately, in the last year there have been very few low-output product releases, and only a couple of manufacturers have released new top-tier platforms, essentially monopolizing the high-end market. The following paragraphs expand on the proper selection of a PSU and details on why these units are our recommendations.
How much power do I really need?
Overall, the best way to select a PSU is based on both objective (e.g. wattage, performance) and subjective (e.g. design, modular cables) parameters. This admittedly does require every builder to be capable of making at least an educated guess about the power requirements of the system. However, this is where our guide and advice come in.
Perhaps the biggest mistake that many users make in selecting PSUs is overrating the power requirements of their systems. It is not uncommon for people – even store salespersons and experienced builders – to recommend a 1kW unit to a user with just two (or even one) high-performance GPUs. A system with a single mainstream CPU and a matching video card rarely requires more than 350 Watts. A modern AMD Ryzen-based system with a single AMD RX 6600/NVIDIA RTX 3060 card will hardly reach up to 275 Watts, while it usually idles at 45-55 Watts. And even in a more extreme scenario – say the rather power-hungry Ryzen 9 5950X paired with a GeForce RTX 3090 – is going to stop short of 650W even in pathological loads.
Meanwhile “wattage calculators”, though an improvement from blindly guessing, are usually simple tools that get their numbers from the design power (TDP) specifications of components. The TDP of a component does not represent the actual power requirements of a component – it’s at best a broad guideline – and it also is next to impossible to place every single component of a system under maximum stress simultaneously. However, keep in mind that a PSU needs to operate at around half load for optimal performance. With that in mind, while the recommendations of the online tools and calculators may be overestimated, they’re not overly so. Selecting a unit of the wattage they recommend is not usually a bad idea, as the recommendation usually is twice the actual power requirements of the system. The common mistake is that users usually seek to buy a significantly more powerful unit, thinking that having extra power helps, and end up with a severely oversized PSU for their system that will be both more expensive to purchase and unable to perform as it should.
If you can measure the actual power requirements of your system, keep in mind that you should not buy a unit that will frequently operate near its maximum capacity. Just as you would not run your car constantly near the red line, a PSU should not be under maximum stress for prolonged periods. A high-quality PSU can withstand it, but just because it can does not mean it should. Again, all switching PSUs deliver their maximum efficiency at roughly 50% of their rated capacity. Running a PSU at over 90% capacity for prolonged periods of time will not only reduce its performance but it will also make it hotter, louder, and decrease its expected lifespan.
EVGA 450 BR 450W ($35)
EVGA 450 GM 450W ($80)
Seasonic PRIME Fanless PX-450 Platinum ($217)
Our primary recommendation in this category is the EVGA 450 BR. Although it is a rather basic unit with the lowest 80Plus certification standard, it still is a step forward since last year’s EVGA N1 400W. It is a basic but proven design that comes from a reputable manufacturer that supports it with a good 3-year warranty. It currently retails for $35 – $5 lower than what the N1 was selling for last year, making it an exceptional deal for systems with low power demands.
For those seeking something more than just a basic PSU, the retail price for something acceptable nearly doubles. Our recommendation lies again with an EVGA PSU, the 450 GM. Although it shares the same power output as the 450 BR, the 450 GM is significantly more efficient, modular, and EVGA covers it with a 7-year warranty. It also is an SFX PSU, for which we are sure that our recommendation will raise quite a few eyebrows, yet the explanation is straightforward – there simply are no other advanced 450 Watt PSUs that can match the 450 GM’s $80 price tag (or any reasonable price, for that matter). At the very least, the EVGA 450 GM has an SFX to ATX adapter in the packaging, allowing it to be installed in any ATX case.
There are very few high-performance PSUs in this power range, greatly limiting our potential recommendations. One quick search is enough to indicate that PSUs with high efficiency ratings are practically non-existent in this power range, as manufacturers do not want to focus their R&D on products that benefit little from having high efficiency ratings.
Among the handful of candidates here, the Seasonic PRIME Fanless PX-450 is one of the very few designs with a very high efficiency certification, proven electrical performance, fanless operation, great quality, and a lengthy warranty. It is, in our opinion, the best 450W PSU currently available. The only downside here is that the retail price of $217 is ludicrous, even for a fanless 80Plus Platinum certified unit. But if money is no limit, then it’s hard to beat the PRIME.
EVGA 510 BP 510W ($40)
Fractal Design Ion+ 2 Platinum 560W ($111)
Unlike the underserved sub-500 Watt range, there is significant demand for 500 to 600 Watt PSUs, and therefore, a wider range of products available. This is a reasonable power range for a typical home entertainment / gaming PC with a single mainstream video card.
Perhaps the most cost-effective choice in this power range comes from EVGA this year, with their new EVGA 510 BP 500+10W unit that is currently retailing for just $40. Although its specifications are not all that great and its performance is just a tad better than mediocre, it comes with a 3-year warranty and retails for just $40, making for an amazing amount of bang for the buck.
On the other end of the performance spectrum lies the Fractal Design Ion+ 2 Platinum 560W PSU. It is a very efficient 80Plus Platinum certified PSU, with great overall performance, a modular design, and very reliable construction. Once again, the retail price nearly triples, with the Ion+ 2 560W retailing for $111, yet it is undeniably a much better investment if you are planning on keeping your hardware for many years to come.
be quiet! Pure Power 11 600W ($70)
Seasonic FOCUS PX-750 ($150)
PSUs with an output between 600 and 800 Watts are very popular amongst gamers and overclockers. They provide enough capacity for high-end components like 16 core processors and 350 Watt video cards and offer a lot of headroom for overclocking as well. This power band tends to be popular overall, as the power overhead provides a sense of security.
There are very few low-cost products of acceptable quality in this power range, as most companies focus their efforts on developing fancy and/or high-performance units. Our recommendation this fall lies with the Be Quiet! Pure Power 11 600W PSU. Most may wonder why we are recommending an 80Plus Gold certified unit in our value band – it is because it currently retails for just $70, a price tag lower than that of the lower-rated units of the same series. The Pure Power 11 is a semi-modular, high-performance PSU with great overall performance, so it would be unreasonable to try and save $5-10 to end up purchasing something that is well below its league.
For users seeking even better performance, SeaSonic markets one of their most legendary platforms in this power range, the Focus PX-750. It is an 80Plus Platinum certified unit with world-class electrical performance and reliability, which is covered by a 10-year long warranty. Its retail price is steep, at $150 today, yet not unreasonably steep for those who are willing to pay the price for a top-quality part.
Corsair RM850x ($110)
Seasonic PRIME TX-850 ($200)
The 800 to 950 Watts power range is typically reserved for users that want to power more heavily overclocked PCs, and increasingly workstation-focused multi-GPU computers as well. Low-cost alternatives from reputable manufacturers here are becoming scarce – we cannot go very cheap in this power range because we believe that long-term reliability is an absolute must whether we are considering a high-end gaming system or a professional workstation.
Holding steady in the same position as last year, Corsair’s renewed RMx series probably offers the best bang for the buck in this power range. They are very well-made, aesthetically pleasing, powerful, and efficient designs, with excellent power quality figures. The 850W version of the series is 80Plus Gold certified and the price dropped from $135 to $110 since last year, making it an even more reasonable choice for users who value long-term reliability and reasonable overall performance.
For those who want to purchase something that is significantly better than the already great RM850x, SeaSonic again comes to the rescue with the Prime TX-850, one of their best units in this power band. The TX-850 offers unrivaled electrical performance, it features an 80Plus Titanium certification, and is covered by a ludicrous 12-year warranty. It retails for $200, nearly twice the price of the mid-tier RM850x but, once again, it is not an unreasonable price tag to pay for the very best in quality and performance that currently exists in the retail market.
EVGA Supernova 1000 G6 ($150)
Corsair HX1200 ($240)
be quiet! Dark Power Pro 12 1500W ($450)
If you require a PSU with over 1000 Watts of output, chances are that you have at least a couple of high-end GPUs and/or a seriously powerful dual-CPU system with a lot of devices. These PSUs also find use in advanced servers and cryptocurrency mining systems. That being said, the PSU is going to be powering a rather expensive system, the function of which is frequently very important. Units in this power range are also a bit scarce this year, suggesting that the cryptocurrency mining frenzy is having an impact on more than just the GPU market and on our planet.
Considering the above, the definition of a “value” PSU within this power band is rather vague. Any such PSU will have to meet at least basic reliability and performance standards. The product that meets the bare minimum of our expectations is the EVGA G6 Supernova 1000W unit. It is based on a relatively simple platform but it is built with quality parts, granting it its 80Plus Gold efficiency certification and a very long 10-year warranty. It is currently retailing at $150, a more than reasonable price considering the features and power output.
Still, given the kind of expensive systems that a 1000W+ unit would end up powering, it’s not a bad idea to go with a higher efficiency PSU – small losses aren’t quite so small at 1kW – as well as to snag something built to a higher standard of quality overall. The only catch is that moving to something significantly better than the G6 Supernova adds a very significant $100 to the price tag, which is a large difference for just a little bit of power savings. For example, the currently cheapest 80Plus Platinum certified unit that we would recommend is the Corsair HX1200, which currently retails for $240. However, the more efficient Corsair HX1200 also emanates less heat and operates at lower noise levels, which may be points that some users need to consider.
For those craving even more power, if cost absolutely is not an issue, Corsair’s AX1600i still is the performance champion of PC PSUs. However, its retail price multiplied since its release in 2018 and it currently retails for the unreal figure of $850, making it an unreasonable choice for any person who knows the rough estimate of their savings account. Those who really need >1.5kW of power can still opt for the Be quiet! Dark Power Pro 12 1500W, another top-tier PSU that is on the same level as the AX1600i, yet currently retails for $450, nearly half the price.
With SFX units becoming more and more popular with each passing generation, it is only fair that we should include them into this year’s PSU buyer guide. There are still but a few reputable contenders in the SFX market, yet there is healthy competition, with several advanced units becoming available in recent years.
EVGA SuperNOVA 450 GM ($80)
Corsair SF450 Platinum ($115)
This power range should reflect the needs of most users building standard SFX-based entertainment systems. 350-450 Watts are more than enough for an efficient system, even if it has a mainstream range graphics card installed.
In this power range, we are going to recommend the same SFX unit that we recommended to ATX system builders as well – the EVGA 450 GM. With its $80 price tag, it is the most reasonable choice in this power range, especially considering its good 80Plus Gold certification, whereas nearly all similarly priced SFX units come with an 80Plus Bronze certification. Efficiency matters a lot in the confined proportions of SFX units, therefore the EVGA 450 GM lands well ahead of its competition.
Corsair made a very strong entrance into the SFX market with the SF series a couple of years ago. The latest version of the SF450 boasts 80 Plus Platinum efficiency certification, modular design, good power quality, and reasonable price tag are giving the competition a hard time. The SF450 is probably one of the best choices for a 450W SFX PSU when weighing its reliability and performance against its passable $115 price, which also is $10 lower than last year.
Seasonic Focus SGX-650 ($130)
SilverStone SX800-LTI ($220)
SFX units over 450 Watts are usually reserved for those that want to build powerful-yet-compact living room gaming machines with at least one high-end graphics card installed. The more powerful SFX PSUs can handle even the most power-hungry video card these days, making the build of such gaming machines an expensive but possible endeavor.
Alas, there are no cheap options when one wants a powerful SFX PSU. The least expensive PSU that we would recommend to users that expect to power a higher-end graphics card with it is the SeaSonic Focus SGX-650. SeaSonic is a manufacturer that no one dares question the competence and quality of their products, and the retail price tag of $130 is reasonable considering where the competition stands.
SilverStone is a traditional and major player in the SFX market. After all, the company is strongly focused on the design and marketing of SFX cases, so it is only reasonable that they would spend a lot of R&D on SFX PSUs as well. SilverStone offers a lot of SFX units, ranging from very basic products to the monstrous SX800-LTI 800W PSU. With an 80Plus Titanium certification and performance figures that put most ATX units to shame, the SX800-LTI undoubtedly is one of the best and most powerful SFX units in existence. The retail price is hefty, at $220, but we strongly recommend it to users seeking to build multi-GPU gaming setups.