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MSI MAG A850GF 80+ Gold Full Modular Power Supply Review

Introduction :

Power Supply or PSU or SMPS as it is popularly known to us is a very critical component in any type of PC, without PSU a computer cannot function just like a human body won’t function without brain or heart or liver. Specifications, features vary depending on the application but the basic functionality essentially remains the same.

Whether we like it or not, PSU is one of the most neglected components in the entire system, if not always and by everyone, the majority of the time it gets lesser attention than it rightfully deserves. A good PSU is as important as a good engine in a car that is efficient, reliable, and robust. The stability, longevity, performance of your system is ensured by a PSU and therefore, one should always choose the right PSU from a reputed brand with a known track record.

Nowadays there are far more brands as compared to a couple of years ago. What has not changed yet is the fact that the number of OEM manufacturers has more or less remained the same to date. There are a couple of very large and well-known OEMs who cater to almost all major known consumer brands for PSU.

Although brands like Corsair, CoolerMaster, EVGA, Asus, Gigabyte, Antec, XPG, and many more are quite popular and crowd favorites, none of them manufacture PSU on their own. There are a few brands that not only sell under their own brand name but also work as OEMs for a lot of popular brands. Some of them are Seasonic, SuperFlower, FSP, Delta, and so on. One of the largest OEMs is CWT or Channel Well Technologies. These days almost every other gold or bronze rated mainstream PSU is made by CWT.

What we have today with us today is the MSI A850GF 80+ Gold Rated Full Modular PSU Unit. No prizes for guessing that this also is a CWT-made Unit like many others in the market. CWT units are known to be well-built and reliable.

Let us be very clear that we are not going to dissect the PSU to analyze PCB design, components used and solder quality, etc. What we do want to check is how it performs in real-world scenarios. For this MSI was kind enough to send us MSI X299 Prestige Creation Motherboard and MSI Gaming X Trio Geforce RTX 3090 24GB Graphics Card. Without wasting much time, let’s start off by unboxing followed by testing.

Unboxing :
The packaging is pretty standard with a pouch that includes all the modular cables along with a Power cord, PSU Unit, Manual.

Modular Cables Included -

  • 24 Pin ATX : 1

  • 8 Pin CPU EPS : 2

  • 6+2 Pin PCIE VGA : 4 ( 2 x Single 6+2 Pin + 2 x Dual 6+2 Pin )

  • Molex : 1 (4 x Molex + 1 x FDD)

  • SATA : 2 (4 SATA Devices per cable)

  • Power Cord : 1

Closer Look :
Pressed steel casing. Found in Bronze grade PSUs. Would not have hurt to use a better, stronger casing. Although this doesn’t affect the PSU functionality at all, it does help in making the user feel it is of higher quality and more premium in terms of build quality. It is a matter of perception.
On/Off Switch and large mesh for optimum ventilation.
Properly labeled modular connection ports. The main 24 Pin ATX Motherboard connector connects to the PSU via split 18 + 10 pin connectors which are clearly labeled. There are 2 x dedicated 8 Pin EPS CPU connectors followed by 3 x 8 Pin PCI Express GPU/VGA Connectors. Last but not the least, there are 4 x Peripheral/SATA connectors.
If we observe the sticker label above, it is clear that this unit is not a multi-rail unit which means that there are more than 1 rails that provide a + 12V supply. +12V supply is mainly required by CPU and GPUs. Higher current ratings on these rails usually tell us a lot about what the PSU is capable of.

The label above can be a bit misleading. As per the label, there are +12VVGA1 and+12VVGA2 each state's current rating of 40A which adds up to roughly 480W which is not possible for ‘each’ rail. I am assuming the 40A current rating is for both combined. Similarly, for CPU, there are 2 x Rails, namely +12VCPU & +12VMBPH. Again I am assuming 25A Rating for both combined which adds up to 300W. Therefore 480W + 300W for VGA and CPU makes up 780W and the remaining for peripherals. This math makes more sense.

Let’s move on to actually testing to figure out what’s what.

Test Setup -
  • Intel Core i9 9960X (16Core/32Threads)

  • MSI X299 Prestige Creation

  • Corsair Dominator RGB 3600MHz 8GB x 4 DDR4

  • MSI Gaming X Trio Geforce RTX 3090 24GB

  • Custom Water Cooling for CPU

  • MSI MAG A850GF 80+ Gold Full Modular PSU

We manually overclocked the CPU to 4.3GHz on all cores to maximize the current draw under full load. GPU was run at Stock speeds and thanks to ~30c ambient temps, was not throttling and running ~ 1900MHz consistently.

To simulate maximum power draw from the system, we ran the AIDA64 CPU Stress Test and GPUPI 32B GPU Benchmark simultaneously. This ensured that the CPU and GPU both were under max load and drew a lot of Current.

We probed the 12V EPS connector with clamp-on Ammeter to monitor current draw and DMM to monitor +12V voltage rail.

From the picture above, it can be seen that the CPU rail is drawing almost 26.3A current and the +12V rail has dropped slightly to 11.94V. If we do the math, the power draw translates to roughly 314W. This is just from the CPU! Now let’s check out what’s happening with GPU at the same time.

Current draw = 30.9A & +12V Rail = 12.04V

Therefore approx. power draw is roughly 372W. Please note that the 30 series cards tend to spike for a fraction of a second as far as the current draw is concerned and therefore even though our load test shows a power draw of around 372W, we would budget for around 400~420W for RTX 3090 to be on the safer side.

CPU + GPU combined load test results in a power draw of roughly 690W.
Observations and Conclusions :
  • MSI MAG A850GF 80+ Gold Full Modular PSU is a decent unit made by CWT offering decent build quality, performance, and value.

  • Although not a deal-breaker, we would have preferred a stronger casing for the unit.

  • Modular cable quality is decent. Flat cables help a lot in cable management while building systems.

  • Would have liked it if the +12V rail didn’t drop under load for the CPU EPS +12V Rail.

  • GPU +12V rail held pretty solid even under full load.

  • MSI tells us the market price for this unit is Rs.10,000/- Inclusive of GST. Decent price for the overall package.

  • The warranty is 10 years from MSI for this unit. Excellent!

After considering multiple aspects like build quality, real-world performance, warranty period, pricing, there isn’t much to fault within this unit and therefore earns a well-deserved Silver Award from us.


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