Corsair RM750 750W 80+ Gold Modular PSU Review

Voltage Ripple and Efficiency Testing

When reviewing new power supplies at OC3D, we use our dedicated SunMoon PSU Tester, one of the most expensive (if not the most expensive) tools in the company’s arsenal. Here we can see exactly how well a unit can function, looking at its efficiency and power stability, giving us a more in-depth look at the performance of power supply than is possible when using it with standard PC components.

In our video review (next page), Tom will show you this unit in operation, with Corsair’s RM750 hitting its peak wattage output of 750W, showcasing the unit’s efficiency as we tested it at 20%, 50% and 100% loads.
  

  
Efficiency Tests

As an 80+ Gold series power supply, the Corsair RM750 sits exactly where it needs to within our efficiency charts. Over 92% efficiency at 50% loads, 90% efficiency at 100% loads and over 91% efficiency at 20% loads. That’s 90+% efficiency across the board, which is no small feat for a budget-oriented power supply. 

  

Voltage Ripple Tests

Voltage ripple is something that is often underlooked by consumers, being best be described as the stability of specific voltages that the PSU delivers. A PSU with bad ripple will see voltages vary a lot more, which in extreme cases can damage components or shorten their lifespan. Voltage ripple stability is one of the many reasons why you should buy a high-quality power supply and avoid anything that isn’t 80+ certified.

An important thing to note here is that none of the PSUs in this graph is “bad”, even bottom of the chart units like the original Corsair RM1000 (2014) bring usable within your system without any issue. Even so, having low ripple is an important factor to consider when purchasing a new PSU. Cleaner power will help extend the lifespan of your PC’s components by placing each product’s power circuitry under less strain. Even if the RM1000 is usable in a modern system, though we would expect all new high-end power supplies to perform better than this unit in terms of ripple. A lot has changed since the days of the RM1000.

When it comes to ripple the new RM750 sits at in the middle of our charts, sitting above the recently released ROG Thor series when it came to 50% and 100% load ripple. This places the new RM series far ahead of 2014’s RM1000, though our 20% Ripple tests showcased less impressive results. That said, ripple stayed well below 20mV, which is an impressive feat. 

Some of you may be asking this. Why is ripple performance worse than the RMi series? The answer will be clear if you read up on the PSU’s cables on page 1. With the new RM series, the PSU’s cables lack in-line capacitors, a feature which is designed to decrease voltage ripple. Corsair has confirmed that aftermarket Corsair braided cables will offer these missing capacitors and bring these units in line with the RMx and RMi series.