Best Power Supplies

Depending on its overall performance, your PSU plays a big part in determining your system's reliability. So you have to be careful when it comes to picking the right one for your needs. A good PSU should also have the protection features that are able to save your components, including the power supply itself, should something go wrong.

You’ll also obviously have different needs and concerns depending on whether your PSU will be pushing a monster mining rig, an always-in-demand workstation, or a mid-level gaming or productivity PC. We’ll help you find the right power supply for your next rig—whatever it is—below.

News and Product Updates

We reviewed the Seasonic SSR-650PX PSU. While it didn’t win an award, it’s a good balance of performance and price. If you’re looking for a modular PSU with a long (10-year) warranty with enough wattage for mainstream builds, it’s well worth considering.

Why Trust Us?

Tom's Hardware has been reviewing PC hardware for more than two decades. We put each power supply through a battery of tests which measure everything from load regulation to power efficiency, plus key protection features, and much more. We've tested hundreds of models, from sub-500-watt budget units to 1600-watt PSUs with top-of-the-line components and features, so we can separate the best from the unreliable and inefficient models that aren’t worth risking your precious hardware for.

Quick Shopping Tips

First, figure out your wattage requirements. It doesn’t make sense to buy way more potential power than you’ll ever use. You can roughly calculate how much power your new or upgraded system will draw from the wall and look for a capacity point that satisfies your demands. Several power supply sellers have calculators that will give you a rough estimate of your system's power needs. You can find a handful below:

• Cooler Master Power Calculator

• Seasonic Wattage Calculator

• MSI PSU Calculator

• be quiet! PSU Calculator

• Newegg PSU Calculator

You probably don’t need a 1,000-watt PSU, even for an extreme gaming rig. A few years ago, all high-end graphics cards were power-hungry, but this changed with Nvidia's recent architectures. It's simply not necessary to buy a 1kW PSU for a couple of GTX 1080s. A 750W model will do just fine, leaving plenty of headroom for an overclocked CPU as well. Fans of AMD's flagship Radeon cards need to plan for higher power use, pairing them with PSUs featuring greater maximum output.

Check the physical dimensions of your case before buying. Chances are, if you have a standard ATX case, an ATX power supply will fit. But many higher-wattage PSUs are longer than the typical 5.5 inches. So you’ll want to be sure of your case’s clearance. If you have a particularly tiny or slim PC case, it may require a less-typical (and more compact) SFX power supply. We have picks for this form factor below as well.

Want a clean build or working in a tiny case?Consider a modular power supply. If your case has lots of room behind the motherboard, or your chassis doesn’t have a window or glass side, you can of course cable-wrap the wires you don’t need and stash them inside the case. But if the system you’re building doesn’t have space for this, or there’s no place to hide cable mess, it’s worth paying extra for a modular power supply. Modular PSUs let you only plug in the power cables you need and leave the rest in the box.

Model Comparisons: Overall Performance and Performance Per Dollar

In the relative performance charts provided with each one of our PSU reviews, we create an index of sorts that encapsulates overall performance, including load regulation, ripple suppression, efficiency, hold-up time, and the maximum power each PSU can deliver. Hopefully this makes your life easier, since you don't have to decipher several data-heavy graphs to reach your own conclusions.

Relative Performance	Performance Per Dollar

You only need to take a quick look at our index above to see where your PSU of choice stands against its competition. The second-most-important chart (on the right above), derived from the relative performance score, is performance per dollar This should help you when shopping for an upgrade.

Best Cheap PSU ($60 or less)

Bitfenix BF450G

Pros

• Full power at 46°C
• High efficiency
• Good ripple suppression
• Tight load regulation
• Quiet operation
• Excellent build quality
• Compact dimensions

Cons

• Non-modular cable design
• Power factor is a little lower than normal

Verdict

BitFenix's Formula Gold 450W is notably more expensive than competing PSUs like Corsair's CX450 and EVGA's 450 BT. But it's also more efficient and much quieter. If your needs are covered by 450W of output and you don't have a problem with fixed cables, then the BF450G is worth considering for your mainstream PC.

4/5

Review

$59.99Newegg

Alternate Pick:

Corsair CX450 450W

$23.98Newegg

Best PSU: Up to 550 Watts

Corsair RM550x

Pros

• Full power at 48°C
• Efficient
• Ripple suppression
• Silent
• Japanese caps
• Fully modular
• Hold-up time
• Load regulation on the minor rails
• Performance in Advanced Transient Response Tests
• Semi-passive operation
• Warranty

Cons

• Price
• No fan test button
• Distance between 4-pin Molex connectors

Verdict

In addition to very high performance, Corsair's RM550x also features dead silent operation, even under extremely hard conditions. The only major downside of this PSU is its high price, compared to the competition in this wattage category.

4/5

Review

$109.99Amazon

Alternate Pick:

Bitfenix BWG550M

$79.99Newegg

Best PSU: Up to 650 Watts

Seasonic SSR-600TL

Pros

• Resilient to high temperatures
• Efficient
• Ripple suppression
• Load regulation
• Hold-up time
• Accurate Power Ok signal
• 5VSB performance
• Dead silent
• Fully modular
• 2x EPS & 4x PCIe connectors
• Build quality
• Warranty

Cons

• Expensive
• OCP at 5VSB
• Distance between peripheral connectors
• Not top-notch transient performance
• Inrush current with 230V input

Verdict

This is the best passive PSU that money can get you today. It is super efficient, its overall performance puts to shame many high-end active cooling PSUs and it can easily support a strong gaming system. The only downside is the stiff price, but you get what you pay for, with this product.

4.5/5

Review

$199.90Newegg

Alternate Pick:

EVGA SuperNOVA 650 G3

$109.99Newegg

Best PSU: Up to 750 Watts

Seasonic SSR-750PX

Pros

• Price
• Full power at 47°C
• High efficiency
• Good build quality
• Quiet operation
• 10-year warranty
• Compact dimensions

Cons

• EMI
• 3.3V transient response
• High OPP
• 5VSB OCP
• Short distance between peripheral connectors

Verdict

Seasonic's 750W Focus Plus Platinum is a true bargain in the $110 range. It offers superb overall performance, is quiet, employs fully modular cabling, and fits in a compact enclosure. The cherry on top is 10-year warranty coverage.

4/5

Review

$103.65Newegg

Alternate Pick:

Corsair RM750x V2

$109.99Newegg

Best PSU: Up to 1,000 Watts

Seasonic SSR-1000PD Ultra

Pros

• Full power at 47°C
• Efficient
• Ripple suppression
• Load regulation
• Hold-up time
• Accurate Power Ok signal
• Transient response
• Silent (for a 1kW PSU)
• Build quality
• EMI
• Fully modular
• 2x EPS & 8x PCIe connectors
• 2x SATA connectors supporting SATA 3.3 spec HDDs
• FDB Fan
• Selectable semi-passive mode
• Warranty
• Looks

Cons

• Distance between peripheral connectors
• OCP at 5VSB

Verdict

The SSR-100PD Ultra is the best performing PSU with 1kW capacity that money can buy today. We haven't tested of course its Titanium (or ETA-A+) sibling yet, which will most likely achieve an even higher overall performance rating, so for the moment this model is the king of our charts.

4.5/5

Review

$209.90Amazon

Alternate Pick:

Seasonic SSR-1000TR Ultra

$289.99Amazon

Best PSU: Above 1,000 Watts

Corsair AX1600i

Pros

• Full power at 48°C
• Powerful
• Efficient
• Ripple suppression
• Load regulation
• Hold-up time
• Accurate Power Ok signal
• Inrush current
• Silent
• Quality caps
• Fully modular
• Amount of connectors
• Quality fan
• Corsair Link app
• Magnetic side covers
• Warranty

Cons

• Expensive
• Small distance between peripheral connectors
• EMI with AVG detector

Verdict

The Corsair AX1600i is the best PSU that money can buy today, period. It offers top performance on all areas and it uses an innovative platform, which provides us a glimpse at the future of power supply design.

5/5

Review

$499.99Newegg

Alternate Pick:

EVGA SuperNOVA 1600 T2

$599.99Amazon

Best SFX PSU

Corsair SF450

Pros

• Full power at 45°C
• Efficient
• Silent operation
• Ripple Suppression
• Load regulation
• Transient response
• 5VSB performance
• Compact dimensions
• Quality caps
• Build quality
• Fully modular
• Hold-up time
• Warranty

Cons

• Price
• No option to deactivate the semi-passive mode
• No Berg adapter is provided
• ATX cable should be longer
• Some users might not like the lack of an SFX to ATX adapter in the bundle

Verdict

Corsair's SF450 is an SFX PSU featuring amazing performance and very silent operation. It easily takes the top place in the 450W SFX category and its only downside looks to be the increased price, which is justified by the excellent build quality.

4/5

Review

$96.33Amazon

Alternate Pick:

SilverStone SX800-LTI

$175Amazon

MORE: Power Supplies 101

MORE: How We Test Power Supplies

MORE: How To Choose A PSU