ASUS is a respected name in the PC hardware market – with ECS and Gigabyte, the company is in the world’s top three mainboard manufacturers list. Recently, ASUS also engaged into production of other components, previously not selling under the company’s brand, for example, cooling systems, system cases and – that’s what we’re going to discuss today – power-supply units.
Three PSUs from ASUS underwent rigid tests in out laboratory: A-30F, A-30G and A-30H models.
Closer Look at Power Supply Units
I’m not going to examine each of the PSUs separately – visual inspection reveals the fact that the three units we are about to test all have absolutely the same electronics and only differ in their cooling systems.
As you know, the classic and most widespread PSU cooling design uses an 80mm fan installed at the unit’s back panel and working to exhaust hot air to the outside. This design is simple and cheap, but, unfortunately, rather inefficient for high-wattage PSUs either because of bad cooling or because of the noise factor.
Each PSU of the ATX form-factor includes four components in need of cooling: 1) a group stabilization choke, 2) a heatsink with output diode assemblages, 3) a power transformer, 4) a heatsink with switch-type transistors and, sometimes, with a guard voltage regulator (the units are marked out in the snapshot below; the snapshot depicts a 250X1 model from Codegen, rather than any from ASUS, for illustrative purposes – that unit has a lesser component density).
The hottest components are the stabilization choke and the output rectifiers, but in the classic design they are situated aside of the main airflow created by the fan (actually, I met some rare samples of PSUs with these elements placed on the same side with the fan). Thus, a high-powered unit, generating much heat, just needs to have a better airflow for cooling down, i.e. it needs to have a better fan. Meanwhile, the increase of the power of the fan leads to more noise and this is not a factor to appeal to the user.
The junior model from ASUS, the A-30F, follows this design:
Take note of the vent holes – they are not in one side only (usually, the back or front side) as in a majority of PSUs, but are distributed among the sides so that the airflows cool the entire PSU down. There are also smaller holes for cooling the passive PFC choke.