The employment of high-end power supply units will not lose its topicality for a long time. This fact can be explained by the development of ever powerful components which require reliable and solid PSU to support their operation. OCZ company perfectly understands the current tendencies and tries to meet the heightened requirements by designing high-end, reliable and steadfast PSUs. Its ZX-1250 is considered to be the most powerful model in the available line of products, so it will be a perfect supporter for gamers and just enthusiasts willing to 'extract' more from their PCs.
The basic peculiarity of OCZ ZX-1250 is its entirely modular framework. This serves the identifying feature, separating this model from other products. Modular construction presupposes the possibility to toggle off absolutely all cables along with the main, 24-wire ATX power cable. Such framework will be met with approval by those customers who got used to move their PC from one place to the other. The negative aspect of a 'detachable' framework becomes obvious on considerable currents; the decrease of voltage on the plug pins can reach double index. The decrease of short-time sagging on the abrupt increase of +12 channel loading is achieved by means of the additional electrolytic capacitors (integrated to the ATX24 cable) of perceptible volume in +5Vsb, +5, +3.3 channels.
The nominal delivery set is differentiated by the abundance of cables. Among other cables, customers will find six graphics card power cables, additional power cables for the motherboard, cables for drives, and a single ATX24 item. All of the cables are covered by black braiding and accommodate thermo shrinkage on the edges; their length equals to 52 cm which will be sufficient for the majority of systems.
Another framework peculiarity is the partite voltage stabilization at three power channels, including +12, +5, and +3.3. This provided for the avoidance of the mutual influence of channels on the dramatic difference of enabled capacities.
Low-voltage part of this PSU is equipped with a plate-like radiator with five arms. DC-DC voltage converters for +5 and +3.3 channels have found their positions right after the radiator. Each of the converters is based on Anpec APW7073 controller and developed on a separate circuit board. It should be stated that there are no dedicated radiators for these converters due to the moderate loading on channels. The motherboard with module sockets in +12 channel is furnished with 8 electrolytes of 100 mcF, 4 electrolytes of 3300 mcF, and a couple of 2200 mcF. Despite the number of these capacitors, there are more 13 vacancies left on the board.
Testing Methodology and Results
With the purpose to estimate the 'real worth' of PSU OCZ ZX-1250, it is necessary to choose an appropriate testing method. The most optimal alternative is to employ powerful field-effect transistors as the loading. There is a bundle of advantages pertained to this testing method, among which is the real capability to increase the loading power, adding the number of field-effect transistors. Such blocks can be enabled by different channels, while the capacity might be adjusted with an ultimate accuracy to a single watt.
Hence, testing results demonstrated satisfactory stability of channels at different loading capacities. Voltage in +12 channel at the maximal 1248W loading achieved 11.89V, while the noise level showed 46 dB (1 meter apart from the PSU). The noise level does not exceed 35 dB when the loading is lower than 700W. Voltage in +5 channel proved to show promising results as well; the index does not go up 5.1V at low loading capacity, and 4.84V at 150W loading. And finally, voltage in +3.3 channel goes up to 3.17V at 29A current.
At the same time, the beat level at all channels does not surpass the margin of 20 mV, but for the crucial high-frequency surges which triggered the increase of the index up to 50 mV. The admissible maximum for +12 channel is 120 mV, while this index should not trespass 50 mV border on other two channels.