Our load tests utilize a couple of FAST ATE active load testers, and a variety of other equipment such as an oscilloscope, power conditioner, temperature probe, and a power consumption meter. You can read more about our standard testing approach here.
The tests performed are based around six conceivable setups that are out there, and progressively load down the PSU up to the power supply's limits, or 1000W; whichever comes first. Since our test equipment's limits are higher than that of the Corsair CS650M 650W power supply, we can test it to the maximum.
The above tests represent typical loads that we have measured from various systems, and are meant to give a rough idea of where your computer might fall in line with our tests. Please keep in mind that each system is different, and actual loads can vary greatly, even with similar hardware.
Let's start by taking a look at the voltages to see how well this unit did during testing. Starting with the 12V rail, we see 1% regulation from start to finish, with a total drop of .13V. The 5V rail managed to stay within 2% of specification, with a total drop of .06V from start to finish. Moving towards the 3.3V rail, we see that regulation was within 2% of specification, with a total voltage drop of .08V.
DC Output quality for the Corsair CS650M 650W was good, and well within specifications. During Test One, we saw 14mV of noise on our scope. When we increased the loads in Test Two, the ripple climbed to 23mV at around half load. During Test Four, under a load of 650W, the oscilloscope showed a maximum of 33mV of noise on the 12V rail.
The Corsair CS650M 650W is rated for 80 PLUS Gold efficiency. This means that the power supply must perform at 87% / 90% / 87% efficiency, at 20% / 50% / 100% loads respectively. As you can see, the CS650M passed on our bench, and wasn't close to failing at any point.
When Corsair set out to build the CS650M, they had a very strong vision in mind. That vision was to build a quality unit that would attract the masses, and do so while keeping the price down, so that it would appeal to even more potential users. After going over the CS650M, and running it through all of our tests, I have to say that they have done a decent job in doing just that.
The unit performs so well that it gives some enthusiast level units a run for their money in terms of voltage regulation, and DC output quality. There are many high-end units that struggle to stay within 3% of specifications, while the CS650M barely manages to creep into the 2% range.
On the other hand, Corsair also sought to offer the unit at a cheap price. $109.99 isn't bad for a 650W semi-modular unit, but it isn't great either, and therein lays the problem with this unit. There are more than a handful of units that come in cheaper than the CS650M that have the same features, or more. That alone will certainly hinder the minds of many when it comes down to choosing between similar units. New tech products almost always hit the shelf with a little bit of a premium that goes away after a few months.
If that is the case with the CS650M, then it is likely to become a much more attractive offering once it has $10-$15 stripped off the cost of the unit. Until then, it doesn't really stand out in the most crowded segment of the PSU market.