X-bit labs

Powerful Power Supply Units Roundup (page 5)

Category: Other

by Oleg Artamonov

[ 01/28/2005 | 05:24 PM ]

My measurements showed that the efficiency factor of this power supply was about 85 percent under full load, while the power factor almost equaled 1 – thanks to active PFC.

High-frequency pulsations of the output voltage under full load proved to be within the norm on the +5v rail (green line of the oscillogram) as well as on the +12v rail. Their swing was about 25-35 millivolts, while the maximum allowable values are 50 and 120 millivolts, respectively.

If the load is above 300 watts, there became apparent low-frequency pulsations on the +12v rail (100 hertz or the double frequency of the power grid here), but their swing is no more than 40 millivolts under the maximum power load, which is quite normal. On the +5v rail I observed no low-frequency pulsations at all.

The speed of the fans in the unit doesn’t vary greatly under different loads. The maximum speed isn’t high but it suffices for keeping the unit cool.

The most interesting part of our tests is the cross-load characteristics of the unit. Before showing you the results I want to say that the True340P is in fact an intermediate between older ATX12V 1.0 and newer ATX12V 2.0 units. On the one hand, it has the older 20-pin power connector for the mainboard and its maximum allowable current on the +12v rail isn’t as high as with version 2.0 PSUs, but on the other hand it allows for 20 amperes on the +12v, while older units allowed only about 15-18 amperes there.

As you see, the cross-load characteristic of this unit is close to perfect – it is only limited by its specification (i.e. by the maximum allowable wattage and currents) rather than by the deviations of the voltages. The voltages are regulated excellently if we don’t pay too much attention to random out-of-order dots. The +5v voltage doesn’t practically depend on the load at all, while the +12v and +3.3v voltages, although vary, don’t get anywhere close to the limits of their designated ranges. None of the PSUs we have tested so far in our labs have ever had such an excellent result.

So, the Antec TruePower True430P did its best to show you what the independent regulation of the voltages can do. This PSU will suit well for systems that mostly consume from the +5v rail (many Socket A systems belongs here) as well as for systems mainly powered by the +12v rail (all systems with Intel’s processors and with AMD’s Athlon 64). In any case the voltages won’t deviate beyond their standard ranges as often happens with classic PSUs with their group voltage regulation.

Although the True430P with its cross-load characteristic will suit for almost any modern computer, I want to remind you that it is an intermediate between the old and new PSU standard (such units are sometimes referred to as complying with the ATX12V 1.3 standard, but it doesn’t actually describe any units with a total wattage of above 300W), so if you’re shopping for a future-proof unit you may want to consider the NeoPower series, also from Antec. This series complies with the ATX12V 2.0 standard, but provides for a much higher load on the +5v than the new standard describes and this makes them suitable for any computer system, new or old.