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 lower than that of the Corsair AX1200, we can only test it to 1000W.
Taking a look at the voltage results, we see some rather impressive results for quite a heavy load. The AX1200 manages to maintain regulation on the 3.3V rail within 2% during the tests up to 1000W. The 5V rail manages a little better and stays just within the 1% regulation range. The single 12V rail manages 2% voltage regulation as well. While we have seen better voltage regulation out of other power supplies in the past, we haven't seen anything better out of power supplies of this caliber.
Ripple on the 12V rail was spectacular throughout all of the tests. Little can be said here other than, "Wow!" There is less noise on the 12V rail under a 1000W load than you see out of most power supplies under a 200W load. The Corsair AX1200 delivers the cleanest DC output quality of any power supply that we've tested to date.
Even without taking into consideration the total power the Corsair AX1200 provides, the efficiency results of the power supply are great. Not only do they show the power supply is deserving of the 80Plus Gold rating, but it is well within the limits.
While we don't have the equipment to test the Corsair AX1200, there are several conclusions that it is safe to say about the AX1200. Given the results that are shown above, there is no reason that the Corsair AX1200 would have failed any of our tests. The results shown above are all well within specifications. If anything would have been different, the total line regulation on the 3.3V rail may have dropped down to 3% at worst.
It's safe to say that there are few who will need a power supply of such high output. There are just a few power supplies out there that will fit fulfill such a need. One thing is certain, however. With the change in the way enthusiasts build their computers and the components, the need is growing. It is great to see Corsair offer a product fulfill the needs of enthusiasts and to offer it with such high quality as well. The Corsair AX1200 excels at delivering lots of high quality power. Voltage and line regulations are great with efficiency numbers to match it. Bundled with the AX1200 are plenty of connectors and cables to get you going and keep you going in the future.
The only thing that most will have a problem with is the sticker shock from the $299.99 MSRP, but when you're building a computer that requires a power supply of this caliber, you're already expecting that. At least with that hearty investment comes a 7 year warranty which leaves you knowing the AX1200 will be there with you for years and years to come.