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 to that of the Rosewill Fortress 750W 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 .09V. The 5V rail managed to stay within 1% of specification with a total drop of .02V 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 .04V.
DC Output quality for the Fortress 750W was good and well within specification. During Test 1, we saw 17mV of noise on our scope. When we increased the loads in Test 3, the ripple climbed to 29mV at a little over half load. During Test 5 under a load of 750W, the oscilloscope showed a maximum of 41mv on noise on the 12V rail.
The Rosewill Fortress 750W is rated for 80 PLUS Platinum efficiency. This means that the power supply must perform at 90%/92%/89% efficiency at 20%/50%/100% loads respectively. As you can see, the Fortress 750W passed on our bench, and wasn't close to failing at any point.
The Fortress 750W represents another win for Rosewill and once again proves that just because something comes from a house brand that it isn't necessarily a subpar unit. The test results that we have from our Fortress 750W unit are great. The voltage regulation is nothing short of spectacular when looking at the 5V and 12V rails. The DC output quality wasn't too bad either, but could have been a bit better.
It is a shame that Teapo capacitors were used on the secondary side of the Fortress 750W power supply. Every single power supply that we have seen use them has suffered in at least the DC output quality area and some of the voltage regulation area as well. I guarantee you that if Rosewill had requested for 100% Japanese capacitor construction in the Fortress 750W, we'd be staring at one of the best damn power supplies to ever grace our test equipment. Instead, we're left looking at a great unit that was so close to being that much more.
All isn't lost though. Aside from the excellent performance, the Rosewill Fortress 750W power supply represents one of the best values we've ever seen. If the price stays as low as $109.99, it's going to take the market by storm and a lot of manufacturers are going to be left scratching their heads as to why their units aren't selling. If my garage wasn't already overflowing with power supplies, I'd want to stock up on them at that price for future projects or to resell with a bit of a profit and still present them with a good deal.