These PSUs worked together with an APC SmartUPS SC 620 at loads up to 370W (when powered from the mains) and 330W (from the batteries). The UPS switched to the batteries normally. Both PSUs worked at full load without problems.
The output voltage ripple is normal (the allowable limits are marked to the right of the oscillogram). There was also a low-frequency (100Hz) pulsation on the +12V rail, yet its amplitude was negligibly small.
The cross-load characteristics of the junior model are normal for its class (to remind you, these models have joint voltage regulation). In a typical modern PC (that puts a load of 20-30W on the +5V and +3.3V rails combined and the rest of the total load on the +12V rail) the +5V and +3.3V voltages are going to be near the nominal values while the +12V voltage may sag by 3% in especially advanced configurations, e.g. systems with a quad-core CPU and two graphics cards (or a dual-chip card like the Radeon HD 3870 X2).
The senior model doesn’t differ much from the junior one in this test.
The 560 model’s fan speed is lower than 800rpm at loads below 200W. Thus, the PSU is going to be absolutely silent in a real PC when the system is idle. At higher loads the speed is increasing steadily but the PSU is still rather quiet until a load of 300W. After that, the noise of the fan’s impeller and of the airflow becomes audible.
The senior model is similar in its noise characteristics to the junior one despite the more powerful fan: the speed is almost the same at low loads and grows up linearly depending on load in the same manner. This indicates a good implementation of automatic speed management.
The junior model features a good efficiency, about 83%, but the power factor is surprisingly low. PSUs with active Power Factor Correction usually have a power factor of 95-99%. This parameter is of little importance for the end-user, though.
The senior model has similar results except that its efficiency drops below 80% at full load.
The Intelligent Power 560 and 660 power supplies from AcBel are rather typical representatives of the middle class. They easily deliver the specified parameters and work quietly at low loads (which is good for modern PCs whose power consumption is low in idle mode).
You should realize that this middle class has been formed as the result of the PSU manufacturers’ rush towards higher and higher wattage ratings whereas real-life systems, except for enthusiasts’ configurations with Freon coolers etc, do not need that much power. That’s why these AcBel power supplies with wattage of about 500W will be an optimal choice not only for mainstream PCs but also for advanced gaming systems that include senior CPU and graphics card models. For example, Intel’s dual-processor Skulltrail platform consumed slightly more than 400W in our tests.