MSI MAG A850GL PCIE5 850W PSU Review

Part Analysis

General Data
Manufacturer (OEM) CWT
Platform GPX
PCB Type Double-Sided
Primary Side
Transient Filter 2x Y caps,2x X caps, 2x CM chokes, 1x MOV,1x Power Integrations CAP200DG (discharge IC)
Inrush Protection NTC Thermistor SCK-056 5Ohm & Relay
Bridge Rectifier(s)
1x Diodes GBU1506 (800V, 15A @ 125°C)

2x Great Power GP28S50 (500 V, 28 A @ 150 °C, Rds (on): 0.125 ohm) &
1x SPN5003 FET (for reduced no-load consumption)

APFC Boost Diode
1x CRMICRO CRXI06D065G2 (600V, 6A @ 167°C)
Bulk Cap(s)
1x CapXon (420V, 560uF, 2000h @ 105°C, HP)
Main Switchers
4x Silan Microelectronics SVF20N50F (500 V, 12.6 A @ 100 °C, Rds (on): 0.27 ohm)


1x Texas Instruments LM393

APFC Controller
Champion CM6500UNX
Resonant Controller Champion CM6901X
Primary side: APFC, Full-Bridge & LLC converter
Secondary side: Synchronous Rectification & DC-DC converters
Secondary Side
+12V MOSFETs 6x Infineon BSC014N04LS (40V, 107A @ 100°C, Rds(on): 1.4mOhm)
5V & 3.3V DC-DC Converters: 4x UBIQ QM3054M6 (30V, 61A @ 100°C, Rds(on): 4.8mOhm)

PWM Controller: ANPEC APW7159C

Filtering Capacitors Electrolytic: 10x Elite (2,000h @ 105°C, PF),
5x CapXon (2-5,000 @ 105°C, KF),
Polymer: 27x CapXon
Supervisor IC IN1S429I – DCG
Fan Model Martech DF1202512FDHN (120mm, 12V, 0.42A, Fluid Dynamic Bearing Fan)
Standby PWM Controller Power Integrations TNY287PG

These CWT’s GPX platform upgraded to the ATX v3.0 and PCIe 5.0 transient response requirements. On the primary side, a full-bridge topology is used instead of a half-bridge one. Since full-bridge is more expensive, CWT used four affordable main switching FETs. This way, the total cost of these four FETs is lower than that of two higher-quality ones. On the secondary side, all FETs are of high quality since there is no room for downgrades there.

The PCB is small, but there is still plenty of space between parts for efficient cooling. Unlike other CWT platforms, this one has heatsinks on the secondary side. These two heatsinks cool down the FETs generating the +12V rail, which are installed on the PCB’s solder side. Speaking of the solder side, soldering quality is generally good. The build quality is decent. MSI didn’t use top-notch parts, on the primary side and part of the secondary side, to keep the cost down. However, the Elite caps on the secondary side won’t have a problem outliving the product’s warranty under normal operating conditions. When there is no budget for Japanese caps, Elite and Teapo caps are the best alternatives.

I would prefer if MSI used a better fan. Yes, it has a fluid dynamic bearing, according to its manufacturer, but a Hong Hua fan would be way better.

Pages ( 3 of 11 ): « Previous12 3 4567891011Next »

Related Posts

Leave a Reply

Your email address will not be published. Required fields are marked *