MSI MPG A1000G/A850G/A750G PCIE5 Power Supplies

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Computing evolves, and individual components within computers, and so it is time for the power supply to evolve.  ATX 2.0 Power Supplies are in the rear-view mirror as ATX 3.0 Power Supplies make their debut.  MSI is leading that charge, with the launch of its PCIE5 ATX 3.0 compatible power supplies with a real 16 PIN 12VHPWR connector and cable. 

Today is the launch of three MPG PCIE5 ATX 3.0 compatible series PSUs from MSI, as well as two MEG PCIE5 ATX 3.0 ready series PSUs. This article will focus on the MPG PCIE5 series, as we do have one of them in hand to test in a future review, consider this an early product introduction article.  

The new line of power supplies coming from MSI today will specifically be designed to handle the transient power spike burden of high-end GPUs and CPUs pulling lots of power.  These power supplies are designed for the new generation of GPUs, CPUs, and computer build specifications. 

Today MSI launches its MPG A1000G PCIE5 ($199.99), MPG A850G PCIE5, and MPG A750G PCIE5 power supplies. In addition, two MEG PCIE5 series are also launching, the MEG Ai1300P PCIE5 and MEG Ai1000P PCIE5, we will look closer at those power supplies and specifications when we have one in hand to review.

In our introduction article today, we will introduce the new MPG PCIE5 power supplies, detail their specifications, and show you pictures of the MPG A1000G PCIE5 PSU that we have in hand.  This is not a full review today; we will be reviewing the MPG A1000G PCIE5 PSU in our standard rigorous validation methods which takes time to test properly.  Until our review is done, we can show you pictures and specs and see what these new power supplies are all about.

MSI MPG PCIE5 Power Supplies

MSI is launching three distinct power supplies under its MPG branding, the MPG A1000G PCIE5, MPG A850G PCIE5, and MPG A750G PCIE5.  MSI has made the statement that these are made for gamers and creators.  MSI’s MPG branding stands for MSI Performance Gaming and represents MSI’s next to the highest tier of products.  MSI’s MPG brand is all about high-performance gaming with slick looks to match at an affordable price. 

The new key features of these power supplies are that they are ATX 3.0 compatible and PCIE 5.0 ready with 12VHPWR and they have the ability to handle Power Excursions.  What are these technologies?  Let us talk a little about each one before we move on to the specs of the power supplies.

ATX 3.0

All three of the new MPG PCIE5 series power supplies are ATX 3.0 compatible. The ATX specification is defined by Intel, and up to now the most recent version of ATX power supplies has supported up to ATX 2.53. (The ATX 2.0 standard was launched in 2003, yes 2003, that long ago.)  The new ATX 3.0 specification (ATX Version 3.0 Multi Rail Desktop Platform Power Supply Design Guide) implements some much-needed features and features that will benefit both lower power efficiency in power supplies, as well as power supply’s ability to deal with high power components and power excursions.  A really great run-down on ATX 3.0 is explained well on PC World.

It has an output port that is compliant with PCIe 5.0 and Intel PSDG (Power Supply Design Guide) ATX 3.0, also the power supply can hold up to 2x total power excursion and 3x GPU power excursion.

-MSI on MPG A1000G PCIE5


One of the major inclusions with ATX 3.0 is the new PCIe 5.0 12VHPWR connector that is possible on power supplies.  It is a 12-pin power cable with 4 data sense pins for sideband signaling (Sideband Signaling Pins), equally a total of 16-pins.  The full implementation of this can support up to 600W of power delivery, but naturally, if the capacity of the PSU isn’t enough it will be less. The specification provides for a 150W cable option, 300W cable option, 450W cable option, and finally 600W cable option.  

Also, be weary that there will be so-called 12VHPWR “adapters” on some power supplies that exist, which split off to two or more 8-pin PCIe power connectors PSU side to a 12-pin adapter, and not a true 12VHPWR connector pinout power supply side.  These lack the data sense sideband signaling.  Such is the case with the Lian Li SP850 power supply we just reviewed.  That PSU uses an adapter, but power supply side it is just two standard 8-pin PCIe connectors, no data sense side band signaling pins.  All three of the MSI MPG PCIE5 power supplies here support true power supply side PCIe 5.0 16-pin 12VHPWR.    

Power Excursions

The other aspect of ATX 3.0 is its definition for its ability to handle power excursions, also called transient power spikes, which will occur on your devices, like your GPU.  Add-in Card Power Excursions (also called Transient Power Spikes) are defined by the PCI SIG PCI Express CEM 5.0 specification

“The PCIe CEM 5.0 spec addresses the need for occasional power excursions by permitting the card to briefly exceed the existing limits on supply power while still abiding by the power limits on a time-averaged basis. This allows the power supply and Add-in Card to jointly withstand increased power demands with a limited duration and magnitude.” 

-PCI SIG PCI Express CEM 5.0 specification

What this in essence means is that devices like your GPU can exceed the maximum TDP or power delivery of the card by as much as 3x, meaning a 600W power draw can spike to as high as 1,800 watts for a specifically defined set of time, in microseconds.  You could see a 450W card hit 1350W for microseconds, etc.  The power supply must be able to deal with these microsecond power spikes that greatly exceed the maximum power delivery.

PCIe 5.0

How can a power supply be PCIe 5.0 you might ask?  What does a power supply have to do with PCI-Express?  Well, it is the PCI SIG (which defines the PCIe spec) that also defines the power excursions that an ATX 3.0 compatible power supply must comply with over the PCIe 12VHPWR cable.  Therefore, the PCIe 5 spec is simply that, it is a spec, not an actual physical bus, it is a spec that defines what the PSU must adhere with on the 12VHPWR PCIe cable.  In that regard, if you see PCIE5 on the box, you know that the power supply is based on the new specification, and thus supports the 12VHPWR connector and its ability to deal with power excursions as defined by the spec. That is what makes these new MPG power supplies PCIE5 PSUs.

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Brent Justice
Former managing editor of GPUs at HardOCP for 18 years, Brent Justice has been reviewing computer components since the late 90s, educated in the art and method of the computer hardware review, he brings experience, knowledge, and hands-on testing with a gamer-oriented and hardware enthusiast perspective. You can follow him on Twitter - @Brent_Justice You can sub to his YouTube channel - Justice Gaming You can check out his computer builds on KIT - @BrentJustice

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