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There is a lot of marketing fog to get through when choosing the best gaming power supply. Total wattage is only part of the equation. For gamers and overclockers, the power supply often is a point of failure that causes games or the operating system to crash (lock-up).

​PC Power Supply Buyer’s Guide

​​How Much Power Do You Need?

The power supply unit on any personal computer usually is taken for granted. The only time most users think about it is when the computer will not power on, or when the PSU emits a funny noise. It's better to get the funny noise because it's a warning you need a new PSU.

The main reason power supplies fail during games is they lack sufficient capacity for specific components. It's not because they overheat.

Most people think of wattage when it comes to power supplies. Manufacturers know this, so wattage usually is the main feature they promote. The peak wattage often is painted in a fancy, sans-serif font on the side of the unit. In reality, very little of the PSU will be visible after installation.

Peak wattage is really peak output. When considering how much power you need, it's also good to think about continuous output. It's a lower number, so PSU makers don't promote it as much.

There are handy calculators online that can help users determine how much wattage they need to support their computer's configuration. (http://outervision.com/power-supply-calculator) (https://us.msi.com/power-supply-calculator)

Even if a power supply has enough wattage to support a graphics card under stress from a game, it may be a good idea to purchase a PSU with some headroom in case you want to add more components to the computer system in the future.​

​80 Plus Standard

Ecos Consulting created the 80 Plus certification program for power supplies. It is a voluntary certification. The program promotes energy efficiency. If a power supply is 80 Plus, it is certified to be more than 80 percent efficient at 20 percent, 50 percent and 100 percent of rated load. There are some PSU makers that falsely claim to sell 80 Plus products. The Ecova website has a list of units that are certified.

As Linus Sebastian explains in a video for LinusTechTips, if you buy a power supply that is much greater than what your rig uses, the 80 Plus efficiency rating will be skewed.

The 80 Plus rating does not mean the PSU will make your games run faster. The rating means less electricity will be wasted. It's a similar idea to the Energy Star rating on most electronics.

If you really want to get picky, a more efficient power supply should in theory run cooler. The temperature of the power supply could have a slight effect on the internal temperature of the computer case. For an overclocker, this might be important. Periodically, blowing out the dust from inside the computer case and off its components may be more helpful.

Metal designations such as 80 Plus Gold signify higher levels of efficiency and are often used for marketing. Remember the “Y2K Safe” stickers? It's probably not worth it to pay extra just to get a higher level of 80 Plus. Anther odd marketing gimmick power supply makers use is “100 percent Japanese capacitors.” That seems to go back to the so called “capacitor plague.” There is no current proof Taiwanese capacitors are inferior.​

​Modular Power Supplies

​It's pretty hard to find an aftermarket power supply without flat or sleeved cables. The advantage of having flat or sleeved cables is they take up less space, so they are less likely to restrict airflow and are easier to position inside the case. Many computer modders try to hide as many cables from view as possible.

If a power supply is modular, some or all of its cables can be detached. You'll see the terms “non-modular,” “full modular” and “semi-modular” in power supply articles online. Fully modular PSUs have the most flexibility when it comes to cable management. While considering cables, it's also good to think about which connectors your computer setup needs. Older power supply units don't have the connectors today's motherboards and graphics cards require.

Fans and Noise

The main reason people choose fanless or passive power supplies is to reduce noise. That's practical, if you have a water-cooled system. Otherwise, the power supply fan probably is not going to be louder than the CPU, graphics card fans or case fans. The larger a fan is in diameter, the quieter it tends to be because it spins slower than a smaller fan.

Most power supply fans are 135mm, which is more than twice the diameter of a 12 oz. soda can. The fans on a standard Corsair water cooler (which is meant to be quiet) are 140mm. The fans for an LGA 1151 socket CPU, air cooler can be 92mm. The CPU fan probably will be the loudest in the case and have the highest pitch.It is relatively easy to replace a stock fan on a power supply. It will void the warranty, but if noise reduction is a concern, that may be worth it. Tom's Hardware has a tutorial for replacing a fan.

​Rails and Amps

​When PSU makers talk about single rails and multi-rail units, they are referring to voltages. Generally, the +12V rail can connect with fans and graphics cards, the +3.3V rail can connect with DIMMs, graphics cards and other chips, the +5V rail can connect with drives, SIMMs and graphics cards.

A single rail PSU has one +12V rail. A mulit-rail PSU has two or more. Multi-rail configurations have a disadvantage in that they cannot share power among rails, says Marco Chiappetta of PC World.

The disadvantage of a single-rail setup is more likely to surge current into components. A multi-rail setup has a overcurrent protection mechanism that will shut down the whole PSU, if it detects an overload on any rail. A single-rail PSU also has an OCP, but it will take a greater overload to trigger a shutdown.

One argument for single-rail PSUs is users don't have to worry about balancing loads among rails or exceeding individual capacity, says Don Woligroski of Tom's Hardware. Voltage ripple describes the fluctuation of voltage, when a rail is operating. If there is too much voltage ripple in the current traveling to a component, it's life will be shortened. There also is a greater chance of a crash, as Michael Kerns of Gamer Nexus explains. Power supply manufacturers generally don't publish voltage ripple specs. Testing for it is complicated as Aris Mpitziopoulos of Tom's Hardware explains.

​The good news is most quality power supplies have built-in protections such as over voltage protection and under voltage protection.

Another spec power supply makers list is the maximum amperage output of rails as in +12V@54A. The higher the amp number the better. Most graphics card makers don't list amperage requirements. They do list required wattage. For example, a Sapphire Nitro Radeon R9 390 uses 375W, and a 750W power supply is suggested.

​Positioning

The ideal configuration for air cooling in a case is one in which the intake fan sucks cold air from outside, and the output fan blows hot air from the PSU and components out of the case.

One way to make this happen is to mount the power supply on the bottom back corner of the case. Hopefully, there is an intake hole on the bottom of the case. A metal toothed edge, hole saw and a drill can easily solve the problem.

This is the only scenario in which the PSU fan should pull in air. The cold air comes in the bottom of the case, and the hot air from the PSU goes out the back of the case. If the case is sitting on shag carpet or a dusty floor then it's best to put the computer on a desk.

Mounting the power supply so the fan is facing up into the case is a disaster waiting to happen. Screws fall to the bottom of mod cases all the time. Pulling cool air into the PSU with its fan from a hole on top of the case goes against the fact heat rises. It would be like pushing your hands together, counterproductive.

Most power supplies only have one fan. There is only a screen on side of the AC port. If the fan is facing the wrong way in the PSU, just remove a few screws to flip the fan to the proper configuration.

​Gaming Power Supply Reviews

All of the power supplies below are made for motherboards with ATX configuration, which is what most gamers use.

Corsair RM550x​

Overall Rating:

​This brand along with EVGA is a premium brand in the power supply world. The RM550x uses rifle bearings in its 135mm fan which are quieter than ball bearings. It has six different protection mechanisms, so you should be covered on voltage, current, temperature and more. It has a 7-year warranty.

The unit has fan control, so it will not spin when it's not under high load. This also can increase fan life. There is no toggle switch for silent mode on the exterior of the PSU, so software is the only solution.

If you're going for an all-black-case theme, just peel off the Corsair stickers, and you're good to go. Those with two graphics cards running in parallel should at least step up to at least a 650W PSU.

Only having two PCIe connectors is the main negative on this model. For practical gaming purposes, you only have capacity for one graphics card and some kind of add-on card. That definitely is not a future proof setup.

PROS:
  • Fully modular
  • 80 Plus Gold
  • DC output: +3.3V@25A, +5V@25A, +12V@45.8A
  • Continuous power: 550W
  • Peak power: 605W
CONS:
  • Can't configure the +12V rail
  • Not as good as the RM550i
  • Only 2 PCIe connectors

Thermaltake Smart Standard 650W

Overall Rating:

​If there is a budget power supply on the list, this is it. You'll notice the specs are “max” and “peak” instead of “continuous” and “peak,” which is a little suspicious. This is the only non-modular PSU among the reviews. Some people prefer non-modular cables because they are afraid of losing them. The exterior is black except for the stickers.

The Thermaltake has a temperature-controlled fan. This unit has a 5-year warranty. The unit is pretty heavy for a 650W power supply. The fan is smaller than those on its competitors, so it may be a little louder. PCIe enthusiasts should enjoy the six available connectors.

One scenario for buying the Thermaltake is if you overspend on the other rig components to get an SLI or CrossFire configuration. You probably could play current games at maximum settings for at least a year. As soon as games start crashing, it's time to upgrade to a higher-wattage power supply.

PROS:
  • 80 Plus Bronze
  • DC output: +3.3V@24A, +5V@24A, +12V@52A
  • Max power: 650W
  • Peak power: 780W
CONS:
  • Non-modular
  • 120mm fan

Seasonic Snow Silent 750

Overall Rating:

​One of the surprising features on this model is the fluid dynamic bearing fan. It's only a 120mm, but FDB makes up for it in quietness and longevity. It comes with a bunch of protections: OPP, OVP, UVP, SCP, OCP and OTP.

The Seasonic's silent fan mode is selectable via a toggle switch on the connector side. That means you have to open the computer case to change it. This unit has a 7-year warranty. The exterior of the power supply is white to go with the snow theme and lacks the usual wattage bragging.

PROS:
  • Fully modular
  • 80 Plus Platinum
  • DC output: +3.3V@25, +5V@25, +12V@62
  • Combined load on +12V: 744W
  • Total output: 750W
CONS:
  • Silent mode toggle in awkward place
  • Only 4 PCIe connectors

EVGA SuperNOVA 850 P2

Overall Rating:

​Corsair's No. 1 competitor is catching up. This unit has a 10-year warranty. The ball bearing fan is a little loud. The exterior of the power supply is black except for the stickers. The fan guard is old school. Some modders cut off this type of guard with a Dremel and replace it with shiny chrome one. The newer styles cut down on vibration/noise. The silent fan mode switch is on the side with the ports.

The EVGA sacrifices some output on the +3.3V and +5V rails to boost the +12V rail. The power supply has lots of protections: OVP, UVP, OCP, OPP and SCP.

For most gaming setups with two high-end graphics cards in an SLI or CrossFire configuration, 750W can provide adequate output and leave some headroom. Within the EVGA SuperNova series, an extra $20 will get you an 850W model with more future proofing.

PROS:
  • Fully modular
  • 80 Plus Platinum
  • DC output: +3.3V@20A, +5V@20A, +12V@70.8A
  • Combined load with +12V: 849.6W
  • Max power: 850W
CONS:
  • Only 4 PCIe connectors

Cooler Master V1200 Platinum

Overall Rating:

Why would you need a 1200W power supply? If you are well off enough to afford three or four high-end graphics cards to run in a parallel configuration and want a three-panel monitor setup, you will need an extreme power supply. Cryptocurrency mining also requires a super awesome system. (http://www.howtogeek.com/211694/cryptocurrency-miners-explained-why-you-dont-want-this-junk-on-your-pc/)

This power supply has 12 PCIe connectors and has a 7-year warranty. It has a 135mm FDB fan. The Cooler Master is manufacturer by Seasonic. As with the other fans reviewed, the silent fan mode switch is on the side of the PSU that faces the inside of the case.

The exterior of the power supply is black except for the branding. The outer frame of the fan guard is dark silver.

PROS:
  • Fully modular
  • 80 Plus Platinum
  • DC output: +3.3V@25A, +5V@25A, +12V@100A
  • Combined load with +12V: 1200W
  • Max power: 1200W
CONS:
  • Super expensive
  • Fan gets very loud under heavy loads

You may have noticed the power supply manufacturers with the exception of Corsair avoided listing a continuous power spec. The spec most likely to allow for an accurate comparison among the power supplies is DC output for the +12V rail. In the manual for the Cooler Master V1200 Platinum, you'll see the PCIe connectors use the +12V rail only. The CPU also uses the +12V rail exclusively. The other connectors share all three rails.

The reason for not reviewing a power supply with an 80 Plus Titanium rating is those cost more than top end CPUs and many premium graphics cards. Paying that much for a PSU on a high-end rig is like burning a $100 bill. The only significant difference between 80 Plus Titanium and 80 Plus Platinum is the efficiency rating for a 10 percent load. Only 80 Plus Titanium has such a rating.

Conclusion

With the exception of installing a graphics card, installing a power supply probably is the easiest hardware operation computer owners can perform. Plan out how much power and which connectors your gaming system will need before buying a unit, and your rig will be as stable and solid as titanium.

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About The Author

Matt Becker

Tech enthusiast. Providing the best, reviews, news, and rumors on the latest technology and PC gaming.

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