Page 3 - Physical Look - Inside
As always, we opened up our Cooler Master X Silent Edge Platinum 850W power supply to take a detailed look at what is going on inside. Please note that doing this at home will void your 15-year warranty, thanks to the warranty seal Cooler Master applied over one of the attachment screws. It is great it comes with a 15-year warranty, which is by far the longest I have ever seen. The industry standard for performance PSUs is 10 years, but I have seen some offerings go up to 12 years. For your benefit, we cracked ours open, so you do not need to. There are no user serviceable parts inside.
Opening the Cooler Master X Silent Edge Platinum 850W is quite straightforward with the removal of ten screws. Taking out the internal components from the enclosure requires the removal of more. Our photo above shows an overhead view of its internal components. Its OEM is Cooler Master themselves, which is impressive, considering how hard it is to do so. It features an LLC full bridge topology with bridgeless interleave PFC on the primary side and DC-to-DC converters on the secondary side. At first glance, the build quality appears to be excellent. There are six main heatsinks inside and almost no wires. Five of the six are finned and painted black, and they are all are of various sizes, as you can see in our photo above.
Pulling the enclosure apart and we got straight to the internal inspection. The transient filter stage is the first input stage of a computer power supply, so we will take a look at that first. Cooler Master has always done a great job in the past to make sure all their power supplies met or exceeded the recommended requirements, and the X Silent Edge Platinum 850W is no exception. The Cooler Master X Silent Edge Platinum 850W has one metal oxide varistor, two metalized polyester X-capacitors, four ceramic Y-capacitors, and two common mode chokes. This is two times the number of X capacitors and Y capacitors than recommended. Considering some PSUs have missing MOVs, I am happy to see it here as this component is used to stabilize spikes from the AC line.
The active PFC circuit featured on the Cooler Master X Silent Edge Platinum 850W is a bridgeless full bridge design. On the middle heatsink near the rear edge, a vertical PCB is spotted with a Nexperia TEA2208T full wave active bridge rectifier controller. Four Infineon IPT60R022S7 rectifier MOSFETs are used. Each is certified for up to 23A at 140c. These transistors present a maximum resistance of 20 mΩ and typical resistance of 22 mΩ at 25c when turned on according to the manufacturer's data sheet. This on characteristic is called Static Drain-Source On-Resistance, or commonly abbreviated as RDS(on). The more efficient the component is, the lower the RDS(on) value, since it wastes less power with lower resistance.
Further down the line, on the heatsink closest to the outer edge, there is one Infineon IDW10G65C5 silicon carbide Schottky diode as APFC boost diodes attached to it. On the same heatsink, there are two Infineon IMW65R072M1H silicon carbide MOSFETs attached to it. Each is certified for up to 20A at 100c. These transistors' RDS(on) are rated at 94 mΩ maximum and 72 mΩ typical at 25c.
On the primary side, we can see two Japanese brand TDK capacitors. Our 850W version of Cooler Master's latest X Silent Edge Platinum series power supply incorporates two 560µF x 450V capacitors in parallel for an equivalent capacitance of 1120µF x 450V. It is rated at 105c, whereas more value-oriented power supplies usually use 85c rated capacitors.
On the same heatsink closest to the outer edge where the APFC components are located, we can see four Infineon IPP60R070CFD7 power MOSFETs as the main switchers. Each is certified for up to 20A at 100c. It has an RDS(on) value of 70 mΩ maximum and 57 mΩ typical at 10V and 25c.
On the secondary side, as with modern high efficiency power supplies, all rectifiers produce the +12V out, while the +5V and +3.3V outputs are generated from the +12V output using a DC-to-DC converter within the power supply unit. Twelve Infineon ISC010N04NM6 MOSFETs are responsible for generating the +12V output, located at the back of the main board. The ISC010N04NM6's rated continuous drain current is 201A at 100c. It has an RDS(on) value of 1.1 mΩ maximum and 0.82 mΩ typical at 10V and 25c.
The +12V MOSFETS are cooled by a copper contact base through a heat pad that leads to four heatpipes going in eight directions. Heatpipes are supposed to efficiently lead the heat away from its source due to the low heat of vaporization, or phase change energy, of the fluid inside. The heat is then dissipated through a finned design of the outside of the X Silent Edge Platinum's aluminum enclosure.
We can see more Japanese brand electrolytic capacitors from Nippon Chemi-Con and Nichicon rated at 105c on the secondary side. The DC-to-DC converters for the +5V and +3.3V outputs are found on a daughterboard parallel to the rear modular cable sockets panel. Unfortunately, I was unable to identify the specific model number for these MOSFETs.
More components can be found on another daughterboard, perpendicular to the rear modular cable sockets panel, shown in the photo above. On the left, we can see the NXP MC9S08SH8CWJ, which is the MCU for the primary side. The Silicon Labs C8051F380-GQ, on the right, is the MCU for the secondary side. The X Silent Edge Platinum still features analog controllers for the circuits, so it looks like these components are used for temperature monitoring, current load, and efficiency data and feeding them into MasterCTRL software only. Meanwhile, a Weltrend WT7502R monitoring IC provides overvoltage, undervoltage, short circuit protection, and power good signal generation.
The datasheets for all components mentioned in this review can be found on their respective manufacturers' websites.
At the back, we have a large daughterboard covering the majority of the rear panel for the modular cable sockets. All modular sockets at the bottom are soldered directly to the main PCB after the secondary stage. Pin headers join the mainboard and daughterboard to reduce power transmission loss. The output connector configuration can be seen on the previous page. Since this is a passively cooler power supply, there is no fan inside.
Overall, the internal build quality of Cooler Master's X Silent Edge Platinum 850W power supply is practically second to none -- impressive for a first shot at an in-house design, and nothing short of what we would expect from a flagship product from the company. Components are arranged beautifully for optimal cooling with almost no wires running around inside, and solder points on its black PCB is quite clean in general. I would say the Cooler Master-branded, Cooler Master-built Silent Edge Platinum 850W is simply excellent with regards to the selection of components used under the hood.
Page Index
1. Introduction, Packaging, Specifications
2. Physical Look - Outside
3. Physical Look - Inside
4. Minor Tests, Software, Conclusion
