Cooler Master UCP Ultimate 900W PSU

What's Inside?

When we visited Cooler Master back in the summer just before Computex, it claimed to have a Gold rated 90+ efficient PSU already made, but the component cost made it simply unmarketable. The UCP series' design approach is apparently similar to high-end server power supplies, with its synchronised PFC controlling the single 12V AC-DC conversion and subsequent 12V to 3.3V/5V DC-DC converters.

This design idea is the new in-thing for 2008, as other companies have also used it in premium models, like Corsair with its HX1000W for example.

The three large electrolytic capacitors are Japanese made and rated to 85'C, in addition to other smaller electrolytic ones dotted about. For the 3.3/5V DC-DC conversion Cooler Master has used dual independent VRM circuit boards at both ends of the board. In addition, eight (CM is specific about the number) solid state aluminium capped capacitors are used that benefit from a longer life, higher temperature tolerance and faster power response; however they are also more expensive. Cooler Master has placed these on the 3.3V and 5V output stage, as well as the 3.3V conversion stage.

The cooling fins have plenty of surface area, although they aren't nearly as large as we've seen in the Corsair HX1000W for example. As they are all angled towards the rear exhaust grill, airflow is forced in the right direction, and with the fan at the opposite end they should pick up plenty of heat too.


Sat upside down just inside the rear grill is a dedicated 5V standby circuit with its own transformer and independent power board - this is needed for when the PC is off and there is no 12V AC-DC conversion taking place in the main PCB.

Finally, there is also a soft-start circuit that prevents current spikes on high wattage PSUs when the system and PSU all demands power at once. This isn't unique to the UCP, but it's certainly a useful and necessary addition to not prematurely fry your new, expensive power supply.


The Superred CHB12012BS fan is also used in the RealPower Pro series and is a Sleeve bearing model rated to a meaty 2,000RPM and 37dBA at 12V. Thankfully, it will never hits this as Cooler Master has hard limited it to 8V and 1,500RPM at peak output, with everything below 70 percent load limited to just 4V (which defies the fan specification according to Superred's own website) and 800RPM. The 1,100W model, however, does get close to reaching the limits at 1,800RPM and as such should be significantly louder in theory.


There are ferrite cored rings over the 5V cables inside, as well as the 5V standby too, but the 3.3V doesn't have it because it has the solid aluminium capped capacitors on the output to smooth out the voltage ripple. The 12V cables have a range of normal electrolytic capacitors to do the same job as well.