Articles: Cases/PSU

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Cross-Load Voltage Stability

Alas, each PSU was poor in this test.

The VP-550 is only more or less good in terms of its +3.3V voltage. The 5V voltage goes out of the permissible range both at very high and very low loads. As for the +12V voltage, which is the most important one for modern computers, it diverts too much from the required level at low loads.

Besides, the VP-550 was not stable at zero load on the +3.3V and +5V rails.

We’ve got the same picture with the VP-650 except that its +3.3V voltage is even less stable.

The VP-750 produces the worst results in this test. Each of its voltages deflects from the required level by 5% or even more in one or another part of the diagram.

So, Aerocool’s Value series PSUs cannot deliver stable voltages. Although they can power up a computer, you can’t be sure of its stability under any circumstances.

Output Voltage Ripple

Sharing the same hardware platform, the VP-550 and VP-650 could be expected to deliver identical results in this test. However, the three models turn out to be very different here.

The high-frequency voltage ripple of the VP-550 keeps within the permissible range, but there are occasional spikes shooting over the allowable limits.

The same goes for the voltage ripple at the double frequency of the mains. It is not as strong as the high-frequency ripple, but there are still occasional voltage spikes that go out of the permissible limits.

The VP-650 has fewer voltage spikes than the VP-550.

Its low-frequency voltage ripple is always within the norm.

The VP-750 produces the worst results in this test, too. The high-frequency voltage ripple is almost as strong as permitted by the industry standard on the +12V and +3.3V rails, the individual voltage spikes shooting far above the permissible limits.

The same goes for the low-frequency voltage ripple.

Temperature and Noise

Each of the Aerocool Value PSUs is cooled by a 7-blade 120mm Young Lin Tech fan (the DFS122512H model with a rated speed of 1800 RPM).

The speed regulation algorithm differs depending on the PSU’s hardware platform.

The two lower-wattage models have a fan speed of 800 RPM at a load of 50 watts. The fan accelerates linearly right from the start, reaching its top speed of 1800 RPM at a load of near 500 watts. As a result, the fan is audible at a load of 250 watts and noisy at 300 watts and higher.

The Aerocool VP-750 controls its fan more efficiently. Its start speed is somewhat lower than 750 RPM and remains the same until a load of 250 watts. Then, the fan accelerates linearly, reaching its top speed at a load of 600 watts.

The fan is audible at a load of 400 watts and higher and noisy at 500 watts and higher.

Thus, Aerocool’s Value series is rather noisy except for the VP-750 model which can be viewed as average in terms of noisiness.

Efficiency and Power Factor

The power factor of the VP-550 model is only 94% at high loads, which is a poor result for a PSU with active power factor correction. The VP-650 is better in this respect, having a power factor of up to 98%. That’s close to the typical value of 99%. It is the VP-750 model that has the lowest power factor of the three: 91.3%. This might be expected, though, as the Hiper M600 performed just as poorly in our earlier test.

As for efficiency, the two lower-wattage models have a peak efficiency of 84% and were about 78% efficient at full load.

The VP-750 is more efficient at low and medium loads, but only 77.9% efficient at full load.

Standby Source

The standby voltage of the VP-550 sags by 4% at full load.

The other two models keep this voltage within 3% from the required level. We show you the graph of the VP-750 because the VP-650 is in fact the same in this test.


Aerocool’s Value series is far from impressive. These PSUs are not very efficient and do not deliver stable voltages. They are also noisy, except for the VP-750 model which is, unfortunately, the worst in other parameters.

The VP-650 seems to be less of a failure than its series mates, yet its actual parameters are nothing but mediocre.

The only good news about these PSUs is that they are among the most affordable products with active PFC available on the market. But do you really want to put up with such poor performance?

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