The 10pc load equates to around 90W of load. You may think that's too low for a modern computer, but understand that our Intel Core i7 2600K platform, constituting a complete PC, idles below 60W. The Antec HCG-900 needs about 110W of AC power to deliver to the components some 90W of DC juice. Efficiency is reasonable across the board, jumping up nicely if pulling at least 200W from the supply.
The numbers show that the supply comfortably attains the requirements for 80-PLUS Bronze certification - though we duly note their testing is a little different to ours.
In terms of regulation, we're looking at just how well the supply is able to hold to the various lines. The ATX spec. has a +/- 5 per cent leeway on all but the -12V line.
|10 per cent||+2.9pc||+3pc||+1.9pc|
|50 per cent||+1.8pc||+1.8pc||+1.0pc|
|100 per cent||0pc||+0.4pc||-0.7pc|
Numbers are shown with a percentage rating of just how close the Chroma reading is to the ideal. Figures are solid throughout, with a worst-case 'miss' of 3 per cent.
Regulation - cross-load
How about providing uneven loads that stress particular voltage rails? In the first attempt, we've put 70A on the 12V rails, and 1A on the 3.3V and 5V rails. This can actually be typical for a system heavy on graphics and CPU power. In the second, we've turned the tables and gone for 20A on both the 3.3V and 5V rails - highly unlikely in a real-world environment - and just 2A on the 12V - even more unlikely!
|Cross-load 12V focus||+3.3pc||+3.2pc||-0.2pc|
|Cross-load 3.3V/5V focus||-0.4pc||+0.1pc||+1.6pc|
The numbers are pretty good for cross-load, too, and well within specifications.
|Line/Load (mv - p-p)||3.3V||5V||12V|
|10 per cent||20mV||19mV||25mV|
|50 per cent||30mV||30mV||29mV|
|100 per cent||32mV||35mV||51mV|
The ATX v2.2 spec states that the maximum permissible ripple is 120mV for the 12V line and 50mV for others. The 12V's ripple is actually proportionally lower than the other two, but the absolute value, and the one that matters in terms of specification, is higher, though well within spec.
We've already tested a few other PSUs and noted that the HCG's ripple rating is average. Still, it's easily good enough to meet ATX spec.
|10 per cent||33°C||38°C|
|50 per cent||37°C||44°C|
|100 per cent||41°C||49°C|
No untoward observations for the temperature tests.
We'd normally report the noise rating, but such is the din produced by the Chroma machine - ears are still ringing - that doing so would be completely pointless. However, by pushing the supply as far as possible away from Chroma and giving a subjective opinion, it can be considered quiet at anything under 75 per cent load. Thereafter, it quickly spins up and becomes fairly loud at 100 per cent. We'll look for a better way of reporting this in the future.
Understanding that the Antec HCG-900 is a mid-range power supply whose focus is on smooth 12V power, the numbers paint a positive picture.