Articles: Cases/PSU

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Cross-Load Voltage Stability

The junior model is very stable in terms of the main +12V voltage which stays within 2% of the required level at most loads and never deflects by more than 3%. The other voltages are not that stable, though.

The +5V voltage deviates as far as the maximum permissible level and beyond at near-maximum loads. It is 4% off the required level in the typical load range when there’s a high load on the +12V rail.

The +3.3V voltage never leaves the permissible range but it’s 3% off the necessary value when there is either a high load on the +12V rail or very low loads on all the rails.

The cross-load diagram of the 1050W model looks almost the same.

So, the Cougar PSUs do more or less well in this test, yet we guess that we could expect a Gold-certified PSU to be more than just satisfactory in terms of the stability of its output voltages.

Output Voltage Ripple

The two Cougar PSUs turned out to be very similar to each other in this test, so we will only show you the results of the higher-wattage model.

The high-frequency voltage ripple is within the norm, especially on the +12V rail, although the latter is permitted to have a voltage ripple of 120 millivolts as opposed to 50 millivolts on the other two rails.

It’s somewhat different at the double mains frequency: the voltage ripple on the +12V rail is stronger whereas on the +3.3V rail, weaker. Again, there are no voltage spikes shooting over the permissible limits.

Temperature and Noise

The two Cougar PSUs differ slightly in terms of cooling.

The junior model is cooled by a 140mm 7-blade Power Logic fan (it is the PLA14025S12M model with a rated speed of 1500 RPM).

The fan is almost identical to the one in the CMX 1200 model with its square impeller blades you don’t often see in other fans. The speed rating is the only difference. Thanks to the higher efficiency of the GX series, the cooling fan can be slower and has a speed rating of M (medium) instead of H (high).

The senior model’s fan looks dramatically different. It has an intricately shaped frame, two extra blades, and a different shape of the impeller with fancy grooves. Oddly enough, it has the same marking “PLA14025S12M”.

Notwithstanding their external differences, the two fans turned out to be very similar in behavior. Their speed regulation works in the same way and they seemed to be identical in terms of acoustic comfort. That’s why we only show you the speed and temperature diagram for the senior model only.

Each fan starts out at a rather low speed of 750 RPM. And in each PSU the fan keeps its initial speed until a load of 600 watts and smoothly accelerates thereafter. The fan of the senior PSU model has a top speed of about 1400 RPM whereas the junior model’s fan accelerates to about 1250 RPM. The fans rattle a little when working, but you can only hear this from a short distance. There is normally no discomfort from those sounds.

Considering their high wattage, the Cougar PSUs can be called rather quiet. They are but slightly louder at full load than the lower-wattage Cooler Master we’ve discussed above.

The low noise level comes at the expense of temperature. The difference in temperature between the incoming and outgoing air is the largest among all the PSUs in this review. That’s the consequence of the high wattage, slow cooling fan and low (for this product class) efficiency.

Efficiency and Power Factor

The two PSUs are similar to each other in this test, too, so we only publish the diagram of the higher-wattage model.

The power factor is typical of a PSU with active power factor correction, reaching 99.6% at high loads.

As for efficiency, the Cougars do not impress. They barely meet the 80 PLUS Gold requirements at the half and full output power. Considering that according to the certification guidelines the efficiency must be measured with 115V mains, which would lead to a lower efficiency than with our 230V mains, there is no reserve of efficiency at all. Neither model could notch 91% efficiency at any load.

Thus, the Cougar PSUs meet the 80 PLUS Gold requirements but do not add anything to them.

Standby Source

The two Cougar PSUs are similar in this test, too. They can easily deliver 4 amperes over the standby line.


The Gold series from Cougar is quiet at any load, up to the maximum one, has low voltage ripple and comes at a modest price compared to similar PSUs.

The downside is that their efficiency is not any better than the basic 80 PLUS Gold requirements while their +3.3 and +5V voltages are not very stable in the cross-load test.

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