ASUSIndisputably one of the largest manufacturers in the PC enthusiast industry, ASUS is a name that almost everyone will recognise for their wide range of motherboards, graphics cards, CPU coolers and innovations such as the affordable EeePC netbook. However, while ASUS’ exploration into new markets has never really come as much of a surprise to us here at Overclock3D, when we recently got wind that they were planning on releasing their own range of PSU’s our jaws literally hit the floor.

But why the reaction? Well, over the past few years there has been an undeniable increase in companies that have absolutely no previous experience in the PSU market jumping on the bandwagon. This has resulted in the market being flooded with PSU’s, most of which are made in the same factories and all are fighting for a place on retailers shelves. Of course this isn’t necessarily bad for the consumer as more competition often results in price wars and many bargains to be had, but from the side of the manufacturer such competition in an extremely crowded market can be crippling.

Of course, maybe I’m jumping the gun here. After all both OCZ and Corsair went from little more than a memory manufacturers to being some of the most preferred PSU manufacturers (in the UK at least) overnight. It’s totally possible that a large name such as ASUS could do exactly the same. So with an open mind, let’s take a look at the specifications listed on ASUS’ website:

Equipped with four +12V rails, the U-75HA provides enhanced stability. Additionally, the U-75HA is certified with the 80 PLUS specification for great energy efficiency.

Certified with 80 PLUS specification (up to 86% efficiency)
Active PFC delivers environmentally friendly power with a high power factor (PF) of up to 99%

Accurate power rating delivers its full rated power
ATX12V Ver. 2.3 compliant-real four 12V rails provide stable support for high-end graphic cards
Dedicated power circuitry: delivers reliable output to delicate components

13.5 cm ball-bearing fan with auto thermal acoustics noise control
Cable sleeve improves internal airflow within the system.
Hexagon venting holes for efficient heat dissipation

Provides both 6-pin and 8-pin PCI-Express connectors for future upgrade to graphic cards
Rich expandability with 6 SATA, 6 peripherals, 2 FDD, 4 PCI-E and 1 EPS connectors
EPS connector provided for dual CPU usage

Certified with CUS, Nemko, CE, BSMI, TUV, FCC, C-TICK
Protection: OVP, SCP, OCP, NLO, OTP, UVP, OPP

Model No.

Input Range

Output Voltage

Total Output

Input Voltage Range

Input Frequency Range













Max. Load










Max. Output






ASUS Specs

Starting with the basics, the U-75HA is certified as an 80Plus efficiency unit with ASUS claiming levels as high as 86%. Under the new 80Plus rating system this effectively certifies the unit as an 80Plus Bronze PSU, with Silver certification just 2% out of its reach (providing the unit can deliver its 86% efficiency at 50% load).

As the specification table above shows, the U-75HA features four +12v rails rated at 18a each with a maximum load of 648w (54a). This realistically brings the maximum output of each rail down to 13.5a if each rail were to be equally loaded at the same time (as we will be doing during the testing). Interestingly the ASUS website calls these rails “real four 12V rails” which by our definition is highly unlikely as it would require four separate 12v transformers. More realistically the U-75HA has one 12v transformer that is ‘virtually’ split into four with over current protection kicking in at 18a on each of the’ virtual’ rails.

The other main rails: +3.3v and +5v  are both rated at 30a each with a maximum load across both rails of 160w. Although the technique for calculating the amperage output of each rail is not quite as simple as the +12v rails as there are two different voltages to contend with (+3.3v & +5v) , heavily loading the PSU in either direction still leaves a reasonable amount of power for the other rail.

Now let’s move on to the unboxing of the U-75HA and its external appearance.