Tests
We will be comparing the Real Power Pro 850W power supply from Cooler Master against the Silencer 750 EPS12V power supply from PC Power & Cooling. The outgoing supply previously tested with nearly perfect results, but on a system that did not consume as much power. Our first test will be at stock settings on the new system, let’s see how the 750 deals with the increase.


While these numbers are not as impressive as we saw in our initial tests of this power supply, the values are all still well with in spec, and certainly more impressive than 90% of the power supplies out there. However, the system under full load at stock settings consumes only 428 Watts. Granted, this is still more than it saw while overclocked in our previous test, but 428 will seem quite low when compared to the overclocked power consumption. Let’s take a look.


Here you can see that with the exception of the +12V rail, the 750 copes with the extra load very well. In fact, the performance on the +3.3V and +5V rails are just as impressive as we had seen in the past. However, the +12V rail suffers slightly from the increased load, probably because the 8800GTX is requiring far more power from the +12V rail alone than in the previous system. You can see that overall the performance of the 750 is quite impressive on this system. However, in order to power this system, we had to make use of a 2xMOLEX-to-1xPCI-E adapter. This was not too much of a problem for us, but it could be significantly frustrating for users with more peripherals that need power.

Cooler Master Real Power Pro 850W

Testing on this power supply was a little different than the ones we have tested in the past. We did the best we could to get readings on each +12V rail to get a better idea of the overall voltage stability, however it is difficult to trace each +12V lead from the PCB to the connector to isolate each rail. We managed to get readings on three different +12V rails by testing the yellow wires incorporated in the 20+4-pin connector, a standard MOLEX connector, and on one of the PCI-E connectors. First test was done at stock settings.


Here you can see that the numbers are not as impressive as on the Silencer 750 EPS12V power supply, but we have to stress that they are still well within spec. The difference of 4 to 5 hundredths of a volt that we see between the two power supplies really has no practical affect on system performance, it merely looks nicer to be closer to the target values. You can also see that there is a bit of difference between the voltages on each of the +12V rails that we tested. This affirms that the rails we tested were indeed three separate rails. It also shows that some of the +12V rails are going to be loaded more than others. Increasing the system clock speeds does not produce any surprises.


As you can see, all three rail types on the RPP850 suffered very slightly from the increased load. However, the performance of the power supply is essentially the same between stock and overclocked settings. Besides that, there really isn’t too much to say about these numbers.