Just under a year since the specification was first announced, the ATX 3.0 era for power supplies is now underway. The updated version of the Intel-maintained specification introduced several notable changes to PC power supply designs, most notably the introduction of the 600 Watt-capable 12VHPWR connector and associated cabling. Altogether, ATX 3.0 is designed to lay the groundwork for future video cards (and other high-powered accelerators) by providing for a single-cable power connection that can better accommodate the high total and rapid shifts in power consumption a video card can undergo.

The biggest change since the addition of the 12V 6-pin “PCIe” power connector in the late 00s, the ATX 3.0 era has come with some new opportunities, both for computing products and for computing problems. The use of adapters has, in short, not gone well for front-runner NVIDIA, with a small but serious number of incidents of 12VHPWR adapters melting down. Meanwhile on the power supply side of matters, this has been a not-unwelcome boon; not only are native ATX 3.0 power supplies the preferred way to go from a design standpoint, but the adapter problems have helped to underscore this advantage. So for the power supply vendors who are among the first to get their ATX 3.0 designs out the door, there’s no shortage of demand for their latest and greatest wares, as well as a fresh opportunity to innovate and set themselves apart from the competition.

In today’s review, we are taking a look at our first ATX 3.0 power supply – and indeed, among the world’s first: the MSI MEG Ai1300P PCIE5. A beefy, 1300W PSU that is designed to be fully compliant with the ATX 3.0 specification, the Ai1300P is a look at what’s to come for the future of high-end PC PSUs, as the market slowly-but-inevitably incorporates ATX 3.0 compliance in order to feed ever more power-hungry video cards and other PCIe devices.

MSI claims that their unit also is the first ATX 3.0 Ready PSU on the market – and although that may be true by some small margin, it does not really say anything about the product itself. The specifications of the MEG Ai1300P PSU that we are reviewing today are extremely impressive, as expected from the flagship product of a premium brand. So for this review we’ll be examining its overall performance, reliability, and of course, taking our first stab at checking for ATX 3.0 compliance.

Power specifications ( Rated @ 50 °C )
AC INPUT 100 - 240 VAC, 50 - 60 Hz
RAIL +3.3V +5V +12V +5Vsb -12V
MAX OUTPUT 25A 25A 108.33A 3A 0.3A
130W 1300W 15W 3.6W
MSRP $360

Packaging and Bundle

MSI supplies the MEG Ai1300P PCIE5 in a large, sturdy cardboard box that provides ample shipping protection to the product inside it. The artwork on the box is rather simplistic and based on a picture of the unit itself. Information on the specifications and certifications of the PSU can be found on all sides of the box, with the logos at the front advertising its ATX 3.0 support.

Instead of cable ties or straps, MSI supplies a number of plastic wire combs. These are quite a bit tedious to install but the outcome is visually superior to basic tied wires. Inside the box, we also found the typical AC power cable and four black mounting screws.

The MEG Ai1300P PCIE5 PSU is a fully modular design, allowing for the removal of every DC power cable, including the 24-pin ATX connector. Most of the cables have individually sleeved black wires and black connectors. Only the 16-pin PCIe 5.0 12VHPWR cable and one cable with two PCIe 8-pin connectors have black wires but are wrapped in a single sleeve.


Connector type Hardwired Modular
ATX 24 Pin - 1
EPS 4+4 Pin - 1
EPS 8 Pin - 1
PCI-E 5.0 (12VHPWR) - 1
PCI-E 8 Pin - 8
SATA - 16
Molex - 4
Floppy - 1


The MSI MEG Ai1300P PCIE5 1300W PSU

External Appearance

MSI is one of the few companies that has invested so much in the external appearance of PSUs, especially with the MEG series. Most of the chassis is covered with embossed geometrical shapes and triangular patterns, with a few golden parts. The satin black paint is very smooth and resistant to fingerprints. The fan finger guard is entirely custom and part of the chassis itself. Despite the massive power output, the PSU is just 160 mm long, making it compatible with practically any ATX-compliant case.

The sticker with the unit’s electrical certifications and specifications covers about half the top side of the PSU. Decorative golden and black metallic plates can be found on the sides of the unit, which plates are magnetically attached and can be flipped to match the installation orientation of the PSU.


A typical on/off switch can be seen at the rear side of the unit right next to the power connector. The front side of the unit is entirely covered by the numerous connectors for the modular cables. A golden legend is printed on the chassis. The tiny Mini-USB connector sits right above the large ATX 24-pin connectors, with the G.I. (i.e. Gaming Intelligence) legend printed right over it.


Internal Design

The 120 mm cooling fan of the MEG Ai1300P is made by PowerLogic for MSI. It features a hydro-dynamic bearing and, as MSI calls them, “liquid-crystal polymer” fan blades that are supposed to be better balanced and more durable than normal blades. MSI probably could not use a 135 mm fan due to patent restrictions and 140 mm fans do not fit in 160 mm bodies with vertical connector daughterboards, so they had to stick to the 120 mm fan instead.

The OEM behind the creation of the MSI MEG Ai1300P is Channel-Well Technologies, or CWT. They are a very popular and reputable manufacturer of mid-to-high-performance PC PSUs. This platform can be described as a hybrid, as it essentially is a standard analog platform but with extra digital electronics added to it. The digital electronics allow for the monitoring of the unit’s basic performance figures, as well as limited control (fan cooling profile, OCP limits, etc) via the USB interface. What really does stand out is the heatsinks, which do have plenty of dissipation surface but are also designed to be aesthetically appealing – an odd (but not unwelcome) design choice considering they should not be visible to the end user.


Electronic circuitry aside, the platform that the MEG Ai1300P is based upon is quite standard and proven. The filtering stage begins on the rear of the AC switch, with six Y capacitors, two X capacitors, and two filtering inductors. It is more than what specifications require but not overly large for such a design. The filtering stage leads to two large rectifying bridges, which are placed on their own heatsink.


The passive components of the APFC circuitry are two beefy 400V/680μF APFC capacitors made by Nichicon, followed by two filtering coils. The active APFC components are on the longest heatsink of the unit. Four transistors can be found on their own heatsink and these form the full-bridge inversion topology at the primary side of the unit. The output of the main transformer is connected to six power MOSFETs that generate a single 12V rail. The 3.3V and 5V lines are being generated via the DC-to-DC conversion circuits. All of the secondary capacitors, electrolytic and polymer alike, are made by Rubycon and Nippon Chemi-Con.


Overall, one quick takeaway from this is that while ATX 3.0 does require more reliability and performance out of high-end PSUs than past versions of the standard, it's not a radical difference. Consequently, neither are the first designs for ATX 3.0 PSUs. MSI's MEG Ai1300P is still built more or less like any other high-end PSU, for both the good and the bad. Thus while there is certainly room for innovation and optimization here, making an ATX 3.0-compliant PSU does not mean OEMs will have to throw out the rule book on PSU design – at least for units above 1000 Watts.

Our First Foray Into ATX 3.0 PSU Testing
Comments Locked


View All Comments

  • sorten - Thursday, December 8, 2022 - link

    Another reminder of why it's good to stick with mid-range gaming and computing. My 1660Ti draws 120W and my Ryzen 3600 draws 65W. No need for a $350 PSU.
  • TheinsanegamerN - Thursday, December 8, 2022 - link

    How odd, my 5800x3d and 6800xt dont push over 450 watt combined, I dont need a $350 PSU either.
  • Eliadbu - Friday, December 9, 2022 - link

    Even if you had i9-13900k and rtx 4090 you would not need 350$ PSU. At that point it's more a gimmick.
    a good 150-180$ PSU will do the trick.
  • powerarmour - Friday, December 9, 2022 - link

    'New Era' and '1300W' should never go together in the same sentence, folks shouldn't even need these ludicrously overpowered PSU's if the hardware manufacturers gave a damn about the environment.
  • PeachNCream - Friday, December 9, 2022 - link

    They can't talk about that. An entire industry revolves around producing overpriced PC hardware and then using journalism as a supporting strut to add hype and build up demand. It's a necessity to sustain the paychecks of a LOT of people at OEMs, retail chains, reviewer websites, and so forth so you will always get unified messaging hocking the benefits rather than encouraging you to be more sensible. It happens in lots of other industries as well and is a HUGE contributor to why we're burning wrecking our own little proverbial cage through horrific wastefulness without having the ability to leave it for other potentially livable places.
  • GeoffreyA - Saturday, December 10, 2022 - link

    Well, as long as money is man's "unit of energy" on Earth, everything else will be subordinated to filling the coffers. I reckon even worrying about the planet ("we use green, vegan manufacturing processes throughout our business because we care") is of a token nature and only important when it can add more dollars to the corporation's bank balance or social prestige. If ever a time comes when damaging the environment is held to be popular, they'll do that too.
  • Dorkaman - Thursday, December 8, 2022 - link

    Did you try bending the 12VHPWR cable by the end that plugs into the graphics card? I guess many PC builders would like to do that to get a tidier cable routing.

    What I read is that 12VHPWR cables are not meant to be bent by the plug. Or is this just the case with NVIDIA supplied pcie-12VHPWR cable adapters?
  • edzieba - Thursday, December 8, 2022 - link

    The various theories of bent plugs or solder joints or etc all turned out to be incorrect: only plugs that were not fully inserted into the socket were able to actually reproduce the overheating issue (even plugs butchered to disconnect half the pins but inserted fully did not fail at all). Plug it all the way in and there is no issue.
  • crimsonson - Thursday, December 8, 2022 - link

    And try not to put pressure on the cable after installation - mainly for the chassis side cover bending the cable.
  • WaltC - Thursday, December 8, 2022 - link

    So why didn't nVidia ship idiot-proof plugs, then? You know, plugs that latch into place with a satisfying "click" when properly inserted? Lots of differing connectors are made that way.

Log in

Don't have an account? Sign up now