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 Antec HCG-620, we can test it to the maximum.
Antec's HCG-620 does an absolutely amazing job concerning voltage regulation. All three rails manage to stay within 1% of specification from start to finish. There was almost minimal voltage fluctuation across the board and it was just as noticeable on the 3.3V rail as it was the 12V rail, both dropping a mere .03V between tests 1 and 4. The 5V rail only dropped 0.2V between tests 1 and 4.
What the HCG-620 has in voltage regulation, it loses in DC output quality. The noise seen on the 12V rail is higher than that of most of the power supplies we have looked at recently under full load. During Test 1, we see a ripple of 27mV peak to peak on the scope. Moving to Test 2, we see a substantial jump to 39mV of ripple. This is still within the range of what we consider acceptable, but it is rapidly approaching the line of 50mV where we start to get uncomfortable.
During Test 3, we see the HCG-620 go past that line as it reaches 51mV of ripple on the 12V rail. This climbs up even higher to 62mV during the full load test of Test 4. While this is higher than we like to see, it is important to note that this is still well within the ATX specification and only half of the maximum 120mV allowed.
The Antec HCG-620 carries an 80Plus Bronze certification with it. This means that it must be 82%/85%/82% efficient at 25%/50%/100% loads respectively. Our first test is above the 25% load mark, but not too far off and doesn't even hint that it wouldn't pass the first part of the certification. The rest of the tests are within specifications, even if it is getting a little close towards the end.
Antec has a lot of highs with the HCG-620. You've got a quality built power supply with a great selection of cables and connectors. Voltage regulation is top notch across the board and you simply couldn't ask for more, even out of a high end, pure enthusiast grade PSU. Add in the low price and you've got a fairly decent list of reasons to pull the trigger on the HCG-620.
There are also many reasons not to pull the trigger on the HCG-620. The mediocre DC output quality would be one of the most prolific reasons to do so, but there are others that many will consider as well. As the power supply is squarely aimed at gamers, it is easily said that the unit will be tortured for many hours at a time. It's hard to see how you could market a power supply towards someone that is going to push it to the limit, but not include over temperature protection or not make sure it is rated for 100% continuous output at 50C. The HCG also only carries a 3-year warranty and is only capable of 80Plus Bronze efficiency.
What it comes down to is that you can't have your cake and eat it too when it comes to power supplies. If you want the high end power supply with all the features, high efficiency and quality power, you are going to have to pay for it. When it comes to budget power supplies, you have to give a little to take a little and the HCG-620 does a great job of finding a balance between affordability while sacrificing a bit of performance.