Articles: Cases/PSU
 

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Kingwin Lazer LZ-850

Kingwin products have been tested in our labs just once before.

The PSU comes in a brightly painted box that can tell you a lot of technical details about its contents.

Exterior Design

Just another matte-black power supply. That’s the only thing I can tell about the Lazer LZ-850 until turning it on.

The PSU features a modular design with eight identical connectors on its back panel. The connectors are made from transparent plastic.

Although protective caps are not necessary for connectors separated by insulating plastic partitions (there is low chance of short-circuiting neighboring connectors), the Kingwin power supply has them: neat silicone caps.

The connectors are transparent for a purpose: they are highlighted by rather bright LEDs when cables are plugged into them. The PSU fan is highlighted as well. The connectors on the cables are made from transparent plastic, too.

The highlighting color can be changed to blue by means of a switch located near the mains connector (you can see it in one of the photos above; it is a small red lever). You can also turn the illumination off altogether.

Interior Design

There are no peculiarities deserving a particular interest in the electronics of this PSU. It is an ordinary modern model with active PFC, a single-step transformer and dedicated voltage regulation based on magnetic amplifiers. The rather large finned heatsinks are painted gold, but that’s just an aesthetic feature.

Pce-tur capacitors are installed at the PSU output.

Specifications

The 12V rail is split into five “virtual” lines, two of which are rated for a max current of 33 amperes and the other three, for 20 amperes. The combined load capacity of the +12V lines is but slightly lower than the PSU's total output power.

The standby source has a high load capacity, up to 5 amperes. I will check out shortly if it can really cope with such load.

Cables and Connectors

The PSU is equipped with the following power cables and connectors:

  • Mainboard cable with a 20+4-pin connector (51 cm)
  • CPU cable with a 4+4-pin connector (54 cm)
  • CPU cable with an 8-pin connector (54 cm)
  • Graphics card cable with one 6- and one 6+2-pin connector (56+15 cm)
  • Eight identical connectors for additional cables

Included with the PSU are:

  • Two graphics card cables with one 6-pin connector on each (51 cm)
  • Two graphics card cables with one 6+2-pin connector on each (51 cm)
  • One cable with four PATA power connectors and one floppy-drive plug (52+15+15+15+15 cm)
  • One cable with four PATA power connectors (52+15+15+15 cm)
  • Two cables with four SATA power connectors (52+15+15+15 cm)

I can make the same comment as for the Enermax power supply. Few people need a second CPU power cable, so it might have been made detachable. Besides, at least one of the CPU power cables should be no shorter than 60-65 centimeters. Otherwise, it may prove too short to reach the connector in a system case where the PSU compartment is at the bottom and the mainboard is of a full-size form-factor (an extension cable would lower stability, especially in a system with a highly overclocked 4- or 6-core CPU that has high power requirements). This remark refers to other PSU makers, not only to Kingwin, though.

UPS Compatibility

Working with my APC SmartUPS SC 620, this power supply was stable at loads up to 350 watts when powered by the mains and up to 334 watts when powered by the batteries. They had no problems switching to the UPS’s batteries and the UPS was stable.

Output Voltage Stability

The +12V voltage is near ideal. The +5V and +3.3V are not that stable, but do not deflect more than 4%, anyway.

Output Voltage Ripple

The output voltage ripple is within the permissible limits except for occasional spikes which are not going to affect the stability of the PSU (especially as they are partially due to the somewhat inadequate reaction of my inexpensive digital oscilloscope to the high-frequency signal constituents).

Noise

The PSU is cooled by a 140mm fan from Globe Fan. It is an ordinary thing with a 2-pin connection. The abundance of cables you see in the photo is due to the two-color highlighting.

The speed of the fan does not change much until a load of 700 watts, being barely above 750 RPM. Then the fan begins to accelerate but does not reach 1000 RPM even at full load. The power supply is going to speed up its fan sooner in a computer with a top PSU compartment, being warmed up by the hot air from the CPU and graphics card, yet the LZ-850 can be considered a very quiet model anyway.

The noiselessness comes at the expense of temperature. Although cool under low loads, the PSU can heat the passing air up by 15°C and more when under high loads. This is yet another reason for choosing a system case with a bottom position of the PSU for a top-end PC configuration because this ensures better cooling for the PSU as well as for the rest of components.

Efficiency and Power Factor

The PSU is up to 87% efficient. Its efficiency at full load is 84%. This is a good, although not record-breaking, result.

Standby Source

Although the standby source is rated for a current of 5 amperes, its voltage drops below the permissible bottom limit (4.75 volts) as soon as 3.5 amperes. Most other PSUs, although limited to a max current of 3.5 amperes, deliver a voltage of 4.9 volts at that load. The LZ-850 is inferior to them in this respect.

Summary

The good news about the Kingwin LZ-850 is that it has a very quiet fan which is faster than 800 RPM at high loads only (such loads can occur but rarely even in a gaming computer with a couple of graphics cards). The downside is that, although the standby source is rated for a high current, it is really inferior to most opponents with lower current ratings. This drawback can show up in systems with huge amounts of system memory (it is powered by the standby source in Suspend-to-RAM mode) or with a large number of devices powered by USB in sleep mode, which is not a typical scenario.

Otherwise, the Kingwin Lazer LZ-850 is yet another high-quality, stable and even beautiful (in a system case with windows) high-wattage power supply.

 
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