Best Power Supplies 2019

Your power supply (or PSU) plays a major part in determining your system's reliability, depending on its overall performance. So you should be careful when it comes to picking the right PSU for your needs. A great power supply should also have protection features to save your components (including the power supply itself) should something go wrong with your electricity supply or your PC components.

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

Why Trust Us?

Tom's Hardware has been reviewing PC hardware for overr two decades. We put each power supply through a gauntlet of tests that measure everything from load regulation to power efficiency, plus key protection features and much more. We've tested hundreds of units, from sub-$50 (£40) budget models 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 components on.

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 few 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 graphics cards on the high-end of the GPU hierarchy were very power-hungry. But this changed with Nvidia's recent architectures. It's simply not necessary to buy a 1kW PSU for a couple of RTX 2080s. An 800W model will do just fine, leaving headroom for an overclocked CPU as well. Fans of AMD's flagship Vega cards or the newer Radeon VII will need to plan for higher power use, pairing these cards with PSUs featuring greater maximum output.

Check the physical dimensions of your case before buying. Chances are, if you have a standard ATX PC 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 PSU 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 your rig. But if the system you’re building doesn’t have space for this, or there’s no easy place to hide your 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. This should make your life easier, since you won'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 (left) 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 also help you when shopping for an upgrade.

Best Cheap PSU ($60/£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

$23.98Amazon

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

Corsair AX1000

Editor's choice tom's Hardware

Pros

• 80 PLUS Titanium efficiency
• Solid build quality
• Excellent results through our benchmark suite
• Fully modular
• 8x PCIe & 2x EPS connectors
• Sleeved cables
• Selectable semi-passive mode
• Ten-year warranty

Cons

• Expensive
• EPS connectors should use 16AWG wires
• Short distance between the peripheral connectors
• OCP triggering points on the minor rails should be set lower

Verdict

Corsair's AX1000 is one of the best 1kW power supplies available. If you want the highest possible performance matched with quiet operation, don't hesitate to make it the centerpiece of your next build (provided the price doesn't scare you off).

4.5/5

Review

$279.99Amazon

Alternate Pick:

Seasonic SSR-1000PD Ultra

$209.90Amazon

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

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