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MSI MPG A1000G Power Supply Review

The MPG A1000G is MSI's flagship PSU, with enough power to handle any of the current generation GPUs.

(Image: © Tom's Hardware)

Protection Features

Check out our PSUs 101 article to learn more about PSU protection features.

OCP (Cold @ 24°C)

12V: 104A (124.55%), 11.966V
5V: 30.7A (139.55%), 5V
3.3V: 30.2A (137.27%), 3.248V
5VSB: 4.7A (156.67%), 4.990V

OCP (Hot @ 41°C)

12V: 104.2A (124.79%), 11.983V
5V: 30.8A (140%), 5.004V
3.3V: 30.2A (137.27%), 3.247V
5VSB: 4.7A (156.67%), 4.988V

OPP (Cold @ 26°C)

1243.38W (124.34%)

OPP (Hot @ 45°C)

1243.4W (124.34%)


✓ (154°C @ secondary side)


12V to Earth: ✓
5V to Earth: ✓
3.3V to Earth: ✓
5VSB to Earth: ✓
-12V to Earth: ✓


Accurate but lower than 16ms



Surge: MOV
Inrush: NTC Thermistor & Bypass relay

OCP is properly set at 12V, but we cannot say the same for the minor rails, especially 3.3V. There is no point in delivering so many Amps at 3.3V. Lastly, OPP is properly configured, too, and there is over temperature protection. 

DC Power Sequencing

According to Intel’s most recent Power Supply Design Guide (revision 1.4), the +12V and 5V outputs must be equal to or greater than the 3.3V rail at all times. Unfortunately, Intel doesn't mention why it is so important to always keep the 3.3V rail's voltage lower than the levels of the other two outputs.

No problems here since the 3.3V rail is always lower than the other two. 

Cross Load Tests

To generate the following charts, we set our loaders to auto mode through custom-made software before trying more than 25,000 possible load combinations with the +12V, 5V, and 3.3V rails. The deviations in each of the charts below are calculated by taking the nominal values of the rails (12V, 5V, and 3.3V) as point zero. The ambient temperature during testing was between 30 to 32 degrees Celsius (86 to 89.6 degrees Fahrenheit).

Load Regulation Charts

Efficiency Graph

(Image credit: Tom's Hardware)

Ripple Graphs

The lower the power supply's ripple, the more stable the system will be and less stress will also be applied to its components.

Infrared Images

We apply a half-load for 10 minutes with the PSU's top cover and cooling fan removed before taking photos with a modified Fluke Ti480 PRO camera able to deliver an IR resolution of 640x480 (307,200 pixels).

The hottest part is the board holding the 12V FETs. With the fan in operation, the temperatures on this board will be under control, but it requires good airflow. 

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Aris Mpitziopoulos
Aris Mpitziopoulos

Aris Mpitziopoulos is a Contributing Editor at Tom's Hardware US, covering PSUs.

  • vinay2070
    Would AIBs be using the 12 pin GPU connectors for Ada? Or is it just nvidia reference cards? I read that Radeon cards will stick to the existing 8 pin connectors.