MSI MEG Ai1000P PCIe 5 ATX v3.0 Power Supply Review

MSI enters the high-end club with the MEG Ai1000P PCIe 5 power supply.

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MSI MEG Ai1000P PCIe5 ATX v3.0
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(Image credit: © Tom's Hardware)

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Primary Rails And 5VSB Load Regulation

The following charts show the main rails' voltage values recorded between a range of 40 watts up to the PSU's maximum specified load, along with the deviation (in percent). Tight regulation is an important consideration every time we review a power supply because it facilitates constant voltage levels despite varying loads. Tight load regulation also, among other factors, improves the system’s stability, especially under overclocked conditions and, at the same time, it applies less stress to the DC-DC converters that many system components utilize.

Load regulation is within 1% on all major rails, so it is pretty tight. It could be tighter at 12V, though. 

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Hold-Up Time

Put simply; hold-up time is the amount of time that the system can continue to run without shutting down or rebooting during a power interruption.

The hold-up time is long and the power ok signal is accurate and longer than 16 ms. 

Inrush Current

Inrush current, or switch-on surge, refers to the maximum, instantaneous input current drawn by an electrical device when it is first turned on. A large enough inrush current can cause circuit breakers and fuses to trip. It can also damage switches, relays, and bridge rectifiers. As a result, the lower the inrush current of a PSU right as it is turned on, the better.

Inrush current is low with 230V input, but pretty high with 115V. 

Leakage Current

In layman's terms, leakage current is the unwanted transfer of energy from one circuit to another. In power supplies, it is the current flowing from the primary side to the ground or the chassis, which in the majority of cases is connected to the ground. For measuring leakage current, we use a GW Instek GPT-9904 electrical safety tester instrument.

The leakage current test is conducted at 110% of the DUT's rated voltage input (so for a 230-240V device, we should conduct the test with 253-264V input). The maximum acceptable limit of a leakage current is 3.5 mA and it is defined by the IEC-60950-1 regulation, ensuring that the current is low and will not harm any person coming in contact with the power supply's chassis.

MSI MEG Ai1000P PCIe5

(Image credit: Tom's Hardware)

Leakage current is low. 

10-110% Load Tests

These tests reveal the PSU's load regulation and efficiency levels under high ambient temperatures. They also show how the fan speed profile behaves under increased operating temperatures.

Swipe to scroll horizontally
Test 12V 5V 3.3V 5VSB DC/AC (Watts) Efficiency Fan Speed (RPM) PSU Noise (dB[A]) Temps (In/Out) PF/AC Volts
10% 6.530A 1.974A 1.979A 0.99A 99.994 85.609% 0 <6.0 44.53°C 0.979
Row 2 - Cell 0 12.006V 5.066V 3.334V 5.053V 116.82 Row 2 - Cell 6 Row 2 - Cell 7 Row 2 - Cell 8 40.19°C 115.13V
20% 14.083A 2.963A 2.97A 1.189A 199.944 90.96% 0 <6.0 45.41°C 0.993
Row 4 - Cell 0 12.003V 5.062V 3.333V 5.048V 219.779 Row 4 - Cell 6 Row 4 - Cell 7 Row 4 - Cell 8 40.58°C 115.1V
30% 22.029A 3.459A 3.465A 1.388A 299.991 91.918% 0 <6.0 46.59°C 0.996
Row 6 - Cell 0 11.982V 5.06V 3.333V 5.044V 326.286 Row 6 - Cell 6 Row 6 - Cell 7 Row 6 - Cell 8 41.47°C 115.08V
40% 29.922A 3.955A 3.96A 1.588A 399.623 92.367% 0 <6.0 47.24°C 0.997
Row 8 - Cell 0 11.978V 5.057V 3.333V 5.039V 432.642 Row 8 - Cell 6 Row 8 - Cell 7 Row 8 - Cell 8 41.62°C 115.05V
50% 37.485A 4.947A 4.951A 1.788A 499.353 92.349% 0 <6.0 48.83°C 0.997
Row 10 - Cell 0 11.974V 5.054V 3.332V 5.034V 540.71 Row 10 - Cell 6 Row 10 - Cell 7 Row 10 - Cell 8 42.83°C 115.02V
60% 45.213A 5.941A 5.944A 1.989A 599.904 91.849% 786 13.3 43.66°C 0.997
Row 12 - Cell 0 11.946V 5.051V 3.331V 5.029V 653.12 Row 12 - Cell 6 Row 12 - Cell 7 Row 12 - Cell 8 50.24°C 114.99V
70% 52.835A 6.936A 6.938A 2.19A 699.632 91.291% 1146 25.4 44.13°C 0.997
Row 14 - Cell 0 11.934V 5.047V 3.33V 5.023V 766.378 Row 14 - Cell 6 Row 14 - Cell 7 Row 14 - Cell 8 51.14°C 114.97V
80% 60.507A 7.934A 7.932A 2.292A 799.673 90.681% 1493 34.7 44.48°C 0.999
Row 16 - Cell 0 11.929V 5.043V 3.328V 5.019V 881.889 Row 16 - Cell 6 Row 16 - Cell 7 Row 16 - Cell 8 52.58°C 114.96V
90% 68.587A 8.434A 8.416A 2.393A 899.47 90.043% 1792 39.4 44.85°C 0.999
Row 18 - Cell 0 11.911V 5.039V 3.326V 5.014V 998.961 Row 18 - Cell 6 Row 18 - Cell 7 Row 18 - Cell 8 54.17°C 114.92V
100% 76.422A 8.938A 8.93A 3A 999.511 89.529% 2079 43.2 45.62°C 0.998
Row 20 - Cell 0 11.905V 5.035V 3.325V 5V 1117.686 Row 20 - Cell 6 Row 20 - Cell 7 Row 20 - Cell 8 55.69°C 114.9V
110% 84.195A 9.939A 10.017A 3.002A 1100.128 88.743% 2326 47.0 46.78°C 0.998
Row 22 - Cell 0 11.899V 5.031V 3.324V 4.998V 1239.721 Row 22 - Cell 6 Row 22 - Cell 7 Row 22 - Cell 8 57.71°C 114.87V
CL1 0.117A 14.26A 14.322A 0A 121.295 83.348% 698 8.7 42.95°C 0.985
Row 24 - Cell 0 11.994V 5.063V 3.33V 5.086V 145.539 Row 24 - Cell 6 Row 24 - Cell 7 Row 24 - Cell 8 48.88°C 115.13V
CL2 0.116A 21.715A 0A 0A 111.386 81.875% 1285 29.4 43.56°C 0.983
Row 26 - Cell 0 12.007V 5.065V 3.333V 5.109V 136.12 Row 26 - Cell 6 Row 26 - Cell 7 Row 26 - Cell 8 50.64°C 115.13V
CL3 0.116A 0A 21.794A 0A 73.986 74.395% 1370 31.7 44.31°C 0.837
Row 28 - Cell 0 12.022V 5.067V 3.331V 5.059V 99.443 Row 28 - Cell 6 Row 28 - Cell 7 Row 28 - Cell 8 52.49°C 115.15V
CL4 83.927A 0A 0A 0A 1000.076 90.096% 2058 42.8 45.97°C 0.998
Row 30 - Cell 0 11.916V 5.041V 3.33V 5.046V 1112.815 Row 30 - Cell 6 Row 30 - Cell 7 Row 30 - Cell 8 55.92°C 114.9V

The PSU delivered 1,100 wats of load at close to 47 degrees Celsius without any issues, but you should not over-stress it if you want it to outlive the extended warranty. The cooling fan rotated at full speed only during the overload test.

20-80W Load Tests

In the following tests, we measure the PSU's efficiency at loads significantly lower than 10% of its maximum capacity (the lowest load the 80 Plus standard measures). This is important for representing when a PC is idle with power-saving features turned on.

Swipe to scroll horizontally
Test 12V 5V 3.3V 5VSB DC/AC (Watts) Efficiency Fan Speed (RPM) PSU Noise (dB[A]) Temps (In/Out) PF/AC Volts
20W 1.236A 0.493A 0.495A 0.197A 19.996 73.387% 0 <6.0 40.23°C 0.687
Row 2 - Cell 0 12.019V 5.068V 3.335V 5.067V 27.316 Row 2 - Cell 6 Row 2 - Cell 7 Row 2 - Cell 8 37.09°C 115.15V
40W 2.723A 0.691A 0.693A 0.296A 39.994 75.323% 0 <6.0 41.24°C 0.791
Row 4 - Cell 0 12.003V 5.067V 3.334V 5.064V 53.123 Row 4 - Cell 6 Row 4 - Cell 7 Row 4 - Cell 8 37.79°C 115.15V
60W 4.210A 0.888A 0.89A 0.395A 59.992 79.229% 0 <6.0 41.74°C 0.818
Row 6 - Cell 0 12.002V 5.067V 3.335V 5.063V 75.588 Row 6 - Cell 6 Row 6 - Cell 7 Row 6 - Cell 8 38.05°C 115.14V
80W 5.682A 1.085A 1.088A 0.494A 79.942 81.888% 0 <6.0 43.29°C 0.836
Row 8 - Cell 0 12.021V 5.067V 3.335V 5.062V 97.633 Row 8 - Cell 6 Row 8 - Cell 7 Row 8 - Cell 8 39.31°C 115.14V

Efficiency under light loads should be higher. We would like to see three out of four tests with over 80% efficiency. 

2% or 10W Load Test

From July 2020, the ATX spec requires 70% and higher efficiency with 115V input. The applied load is only 10W for PSUs with 500W and lower capacities, while for stronger units, we dial 2% of their max-rated capacity.

Swipe to scroll horizontally
12V 5V 3.3V 5VSB DC/AC (Watts) Efficiency Fan Speed (RPM) PSU Noise (dB[A]) Temps (In/Out) PF/AC Volts
1.472A 0.255A 0.255A 0.053A 20.115 73.301% 0 <6.0 25.77°C 0.678
Row 2 - Cell 0 12.032V 5.06V 3.326V 5.061V 27.451 Row 2 - Cell 6 Row 2 - Cell 7 23.78°C 115.15V

With super-light loads, the platform delivers high efficiency. 

Efficiency & Power Factor

Next, we plotted a chart showing the PSU's efficiency at low loads and loads from 10 to 110% of its maximum rated capacity. The higher a PSU’s efficiency, the less energy goes wasted, leading to a reduced carbon footprint and lower electricity bills. The same goes for Power Factor.

Efficiency is high enough with normal and super-light loads, but not so high with light loads. Moreover, the APFC converter needs tuning for higher PF readings with 230V input. 

5VSB Efficiency

Swipe to scroll horizontally
Test # 5VSB DC/AC (Watts) Efficiency PF/AC Volts
1 0.1A 0.511W 76.183% 0.053
Row 2 - Cell 0 5.108V 0.671W Row 2 - Cell 3 115.16V
2 0.25A 1.276W 78.775% 0.123
Row 4 - Cell 0 5.104V 1.62W Row 4 - Cell 3 115.16V
3 0.55A 2.804W 79.183% 0.235
Row 6 - Cell 0 5.097V 3.541W Row 6 - Cell 3 115.15V
4 1A 5.087W 79.344% 0.339
Row 8 - Cell 0 5.086V 6.411W Row 8 - Cell 3 115.15V
5 1.5A 7.612W 79.897% 0.398
Row 10 - Cell 0 5.074V 9.529W Row 10 - Cell 3 115.16V
6 3A 15.111W 78.062% 0.482
Row 12 - Cell 0 5.037V 19.357W Row 12 - Cell 3 115.15V

The 5VSB rail is not efficient and this is a great shame!

Power Consumption In Idle And Standby

Swipe to scroll horizontally
Mode 12V 5V 3.3V 5VSB Watts PF/AC Volts
Idle 12.043V 5.056V 3.323V 5.057V 4.15 0.252
Row 2 - Cell 0 Row 2 - Cell 1 Row 2 - Cell 2 Row 2 - Cell 3 Row 2 - Cell 4 Row 2 - Cell 5 115.16V
Standby Row 3 - Cell 1 Row 3 - Cell 2 Row 3 - Cell 3 Row 3 - Cell 4 0.012 0.001
Row 4 - Cell 0 Row 4 - Cell 1 Row 4 - Cell 2 Row 4 - Cell 3 Row 4 - Cell 4 Row 4 - Cell 5 115.16V

Vampire power is low. 

Fan RPM, Delta Temperature, And Output Noise

All results are obtained between an ambient temperature of 37 to 47 degrees Celsius (98.6 to 116.6 degrees Fahrenheit).

(Image credit: Tom's Hardware)

(Image credit: Tom's Hardware)

The fan speed profile is not aggressive, but the 120mm fan has to spin at high speeds under harsh conditions, to handle the thermal loads. 

The following results were obtained at 30 to 32 degrees Celsius (86 to 89.6 degrees Fahrenheit) ambient temperature.       

(Image credit: Tom's Hardware)

(Image credit: Tom's Hardware)

At normal operating temperatures, close to 30 degrees Celsius, the PSU is silent with up to 500W loads. With more than 650W at it enters the 30-35 dBA zone and the 40 dBA mark is passed with 860W and higher loads. As we already stated, with a larger fan, noise output could be lower at high loads. 

MORE: Best Power Supplies

MORE: How We Test Power Supplies

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Aris Mpitziopoulos
Aris Mpitziopoulos
Contributing Editor

Aris Mpitziopoulos is a contributing editor at Tom's Hardware, covering PSUs.

9 Comments Comment from the forums
  • tummybunny
    Thanks for a fantastic and very detailed review. Something that isn't mentioned though is one of the really interesting new features of ATX 3.0.

    https://www.techpowerup.com/292563/intel-atx-3-0-16-pin-power-connector-for-pcie-gen5-is-smart-has-four-power-delivery-variants?cp=2

    "The 12VHPWR connector has 12 electrical pins and 4 side-band pins, for a total of 16 pins. The side-band pins enable low-fi communication between the power-supply and the graphics card, and two of these pins, labeled "SENSE0" and "SENSE1," let the graphics card know what kind of connector is plugged in, so it can accordingly adjust its power-management."

    What difference does this make to GPU performance? Perhaps you could argue it's something better discussed in a GPU review but I would like to hear about it one way or another.
    Reply
  • Hresna
    Great PSU coverage… although the standard formula I think misses some aspects of a complete review…

    For instance this model offers an MSI feature they all “gaming intelligence” via the USB connector… no mention of this in the article or how it works, what it does.

    I’ve been a longtime fan of Corsairs ‘i’ series which also use USB as the enabler, for the simple fact that it gives power output readings in hwinfo64 which is a fanstastic tool for dialing in power budgets, overclocks/undervolts, or just… those of us who like numbers and data. I can do without the iCUe software, which thankfully isn’t needed for this.

    Does MSI’s GI do that also?

    It’s extremely difficult to find PSU models with these sorts of features. At least the ‘i’ thing seems to be catching on and might serve as a semi-reliable indicator between manufacturers.
    Reply
  • halfcharlie
    Hresna said:
    For instance this model offers an MSI feature they all “gaming intelligence” via the USB connector… no mention of this in the article or how it works, what it does.

    What's this on the first page then?
    "there is compatibility with the MSI Gaming Intelligence application, through which you can adjust several settings, like the fan's speed and toggle on/off the single +12V mode while monitoring the PSU's vital functions and power delivery. " Also google exists.
    Reply
  • CheckYourFacts
    The Author asserts: "The four main FETs are installed into a full-bridge topology. " Where does he get that information from when the vendor says its a "LLC Half Bridge Topology with DC-DC module design "
    https://www.msi.com/Power-Supply/MEG-Ai1000P-PCIE5
    Reply
  • bignastyid
    CheckYourFacts said:
    The Author asserts: "The four main FETs are installed into a full-bridge topology. " Where does he get that information from when the vendor says its a "LLC Half Bridge Topology with DC-DC module design "
    https://www.msi.com/Power-Supply/MEG-Ai1000P-PCIE5
    Considering Aris is one of the top experts/reviewers in PSUs and he did a teardown. I'd believe him over the advertised specs any day.
    Reply
  • CheckYourFacts
    bignastyid said:
    Considering Aris is one of the top experts/reviewers in PSUs and he did a teardown. I'd believe him over the advertised specs any day.

    This is not about the authors reputation, which i know nothing about. It is about journalistic work ethics, his claim is in clear contradiction to the vendor claims.
    Reply
  • bignastyid
    CheckYourFacts said:
    This is not about the authors reputation, which i know nothing about. It is about journalistic work ethics, his claim is in clear contradiction to the vendor claims.
    He opened it up and wrote what he found. If anything that would put the companies ethics in question not the reviewers.
    Reply
  • Lutfij
    CheckYourFacts said:
    This is not about the authors reputation, which i know nothing about. It is about journalistic work ethics, his claim is in clear contradiction to the vendor claims.
    You might want to do a bit of digging and see what Kingston did within the last decade. If you can't find it, I'll help you;
    Kingston sent out SSD's to practically every reviewer known to the (tech)community and once sales drove up to remove practically all units off the shelves, people all stated how the speeds weren't the same as seen by reviewers in spite of the advertised material stating otherwise. A further digging by TekSyndicate/Level1 found out about how cherry picked samples were handed out to help garner a better image.

    That being said, please stop with the needless jabbing, the question falls onto the brand that sent the review sample out, not the person who opened up the unit to report what he'd seen. You're also talking about Aris, here. You're sneezing towards the wind.

    If you believe everything that the brand's marketing material states, then AIO coolers MSI released were the best coolers in the world, not the market, the world.
    Reply
  • Hresna
    halfcharlie said:
    What's this on the first page then?
    "there is compatibility with the MSI Gaming Intelligence application, through which you can adjust several settings, like the fan's speed and toggle on/off the single +12V mode while monitoring the PSU's vital functions and power delivery. " Also google exists.
    Okay so I missed that brief description.
    And yes google exists, but my point was, in a review for something, if you’re going to mention a unique feature - something that sets it apart from its competition - might be worthwhile including a fulsome description and reviewing its functionality.
    So I retract that it wasn’t described at all.
    Reply