Power Delivery
Power delivery or the VRM implementation is the literal elephant in the room when it comes to the MSI X570-A PRO.
The MSI X570-A PRO utilizes an Infineon IR35201 8-phase voltage controller in a 4+2 phase mode. It also uses IR3598 phase doublers. It is essentially a 6 phase design that’s taken to a 4+4+2 phase configuration via the use of doublers. ONSemi 4C029N 46A MOSFETs are used for vCore. The SoC MOSFETs are QA3111N6N from UBIQ, which are rated for 59A. This brings our total vCore power output to 368w, theoretical. While technically enough power to push a 3950X, even overclocked, you would be running the VRM’s hard enough that the cooling for the VRM’s will become inadequate. Indeed, I’ve seen some data to that effect.
However, our testing utilized a 3900X, not the 3950X. As a result, we weren’t pulling quite that much power. That said, we did see temperatures of 115c or 239F. I never saw any signs of throttling, as you’ll see from the benchmarks. But, the test environment was literally the best-case scenario for this board. In a chassis, it would likely be far worse, and hitting 125c or exceeding it would certainly become possible, even on a 3900X.
It is my opinion that this VRM is not recommended for 12c and 16c CPUs without some form of good case cooling or airflow in this area. Partly, this comes down to the selection of components used in the VRM implementation but it also comes down to the VRM cooling itself. The heat sinks are anemic. They are mounted with screws but have a bushing of sorts around them allowing for a great deal of movement. They do not make the best contact. I haven’t pulled them so I can’t see whether or not the thermal interface for the heat sinks is decent or not. Regardless, airflow over these heat sinks is absolutely essential for operation. I tested the MSI X570-A PRO on an open-air test bench with a 120mm fan for VRM cooling. Without that, my temperatures would have been far worse.
Again, looking at what the solution is rated for, these VRM’s have to be run uncomfortably close to their maximum output in order to handle something like a 3950X or even a 3900X that’s overclocked. This is likely going to be the case with the 5900X and 5950X as well. I don’t think very many people that buy $139 motherboards buy $800 CPU’s, but you never know.
I personally would limit the use of this motherboard to at the most, a 12c CPU being run at stock speeds. It’s also worth noting that this motherboard is probably better for those using air cooling as you will have less overall airflow over the motherboard utilizing watercooling. Of course, your mileage may vary base on chassis design.
Furthermore, this motherboard was bought by another reviewer here and used for a while with a 3950X. He was kind enough to take and provide thermal images of the VRM’s when in operation. It doesn’t look good. The VRM temperatures shown are at 117c and 114c. This is in line with what I saw on my test bench, albeit with active air cooling over the VRM and a 3900X overclocked to 4.2GHz all core at 1.385v. Anyone needing 1.4v will likely see even worse results.
The VRMs: Good or Bad?
So, what does this all mean? Is the VRM implementation on the MSI X570-A PRO bad? I don’t think it’s of necessarily poor quality, however, it may be inadequate for use cases where overclocked 12 and 16 core CPUs would be used. But is it bad? Yes, and no. It isn’t made with shoddy components, nor is it somehow unreliable electrically speaking. However, the cooling is inadequate in some scenarios and configurations when compared to its peers in the same price range.
I won’t pretend to know all of the possible motherboard VRM implementations out there. However, when compared to other motherboards from other brands in the same tier, most use MOSFETs that are rated for 55A or more. Others may be rated for 46A as these are, but more phases are in use. Thus, those VRM implementations won’t have to be run as hard and probably don’t look like an episode of Forged in Fire under a thermal camera.
I hesitate to call the VRM “bad”. I think it’s fair to say that it is certainly a weak point of the MSI X570-A PRO as designed. However, it doesn’t necessarily make this motherboard a bad choice.
