Real Power Pro is the high-end power supply series from Cooler Master, featuring models from 550 W to 1,250 W. We reviewed the 850 W model (a.k.a. RS-850-EMBA), which features a big 135 mm fan, dual-transformer design and six +12V rails, being targeted to high-end systems featuring three or four video cards. According to Cooler Master this unit was labeled at 50° C and can deliver up to 1,000 W during peaks. Let’s see whether this is true or not and also let’s take a trip inside this unit.

Cooler Master Real Power Pro 850 WFigure 1: Cooler Master Real Power Pro 850 W.

Cooler Master Real Power Pro 850 WFigure 2: Cooler Master Real Power Pro 850 W.

As you can see, this power supply uses a big 135 mm brushless fan on its bottom (the power supply is upside down on Figures 1 and 2) and a big mesh on the rear side where traditionally we have an 80 mm fan. We like this design as it provides not only a better airflow but the power supply produces less noise, as the fan can rotate at a lower speed in order to produce the same airflow as an 80 mm fan.

This power supply, like all high-end power supplies, has active PFC, which provides a better usage of the power grid and allows Cooler Master to sell this product in Europe (read more about PFC on our Power Supply Tutorial). As for efficiency, Cooler Master says that this product has 81% efficiency at 170 W, 85% efficiency at 425 W and 82% efficiency at 850 W. Of course we will measure this to see if what the manufacturer claim is true. Keep in mind that more expensive power supplies have an efficiency of at least 80%. The higher the efficiency the better – an 80% efficiency means that 80% of the power pulled from the power grid will be converted in power on the power supply outputs and only 20% will be wasted. This translates into less consumption from the power grid (as less power needs to be pulled in order to generate the same amount of power on its outputs), meaning lower electricity bills.

The main motherboard cable uses a 24-pin connector (without an option to transform it into a 20-pin one) and this power supply has one ATX12V connector and one EPS12V connector.

This power supply comes with eight peripheral power cables: two auxiliary power cables for video cards using 6-pin connectors, two auxiliary power cables for video cards using 6/8-pin connectors, two cables containing three standard peripheral power connectors and one floppy disk drive connector each and two cables with four SATA power connectors each.

One thing we liked about this power supply is the fact that each cable is properly labeled, especially because the 8-pin video card auxiliary power connector and the EPS12V connector are very similar.

Cooler Master Real Power Pro 850 WFigure 3: Video card, ATX12V and EPS12V cables are labeled.

The number of available connectors is more than enough even for the most high-end enthusiast willing to build a rig with three or four video cards, a very high-end CPU and lots of hard disk drives. One good thing about this power supply is that each video card connector is installed on an independent +12 V rail, which provides a better power distribution and protection. We will talk about this in details later on “Power Analysis” section.

Even though this power supply carries an amazing number of SATA power plugs – eight – for a better power distribution and facilitate the installation of a system with lots of hard disk drives and optical units we think that it would be better if Cooler Master used three cables with three SATA plugs each instead of just two cables with four SATA plugs each.

On this power supply wires on the main motherboard, peripheral and SATA cables are 18 AWG, while wires on the EPS12V, ATX12V and all video card cables are 16 AWG, which is perfect.

On the aesthetic side Cooler Master used nylon sleeving only on all cables, but this protection comes from inside the power supply housing only on the main motherboard cable.

This power supply is manufactured by Enhance Electronics and on their website there is no model that is identical to Real Power Pro 850 W, so it seems that this model is manufactured exclusively for Cooler Master.

Now let’s take an in-depth look inside this power supply.


Gabriel Torres is a Brazilian best-selling ICT expert, with 24 books published. He started his online career in 1996, when he launched Clube do Hardware, which is one of the oldest and largest websites about technology in Brazil. He created Hardware Secrets in 1999 to expand his knowledge outside his home country.