Comparison Cougar GEX PRO GEX PRO 850 vs PCCooler YN YN850

— Active cooling system. Uses a fan that constantly operates to remove heat from internal components. Unlike passive cooling, the active system provides better heat dissipation and stability under high loads, preventing overheating. However, it creates noise. To eliminate this, fans in such power supplies can have dynamic speed control (AFC – Automatic Fan Control), reducing speed at low power consumption.

— Semi-passive. Active cooling systems with automatic fan shutdown in situations where the load on the power supply is low and heat generation is reduced. Let us remind you that systems of this type are more efficient than passive ones, but they consume additional energy and create noise during operation. Accordingly, at low loads, when intensive cooling is not required, it is wiser to turn off the fans — this saves energy and reduces the noise level.

— Passive(radiators). Compared to fans, radiators have a number of advantages: for example, they do not create any noise and do not require their own power supply (thus reducing overall energy consumption). On the other hand, they are significantly less efficient, as a result — the power of power supplies with passive cooling does not exceed 600 W. In addition, such power supplies are quite expensive.

The diameter of the fan(s) in the power supply cooling system.

The large diameter allows to achieve good efficiency at relatively low RPMs, which in turn reduces noise and power consumption. On the other hand, large fans are more expensive than small ones and take up a lot of space, which affects the dimensions of the entire PSU. We also emphasize that a small fan is not yet a sign of a cheap power supply — quite advanced models can also have such equipment, in order to reduce dimensions.

As for specific diameters, the smallest value that can be found in modern consumer-grade PSUs is 80 mm. The most popular option is 120 mm, this size gives good efficiency and a relatively low noise level at a reasonable price and dimensions. Larger diameters are somewhat less common — 135 mm and 140 mm.

The Cybenetics Lambda Certification System evaluates the noise levels of power supply units (PSUs), providing consumers with information about their acoustic characteristics. As a result, you can rely not only on the efficiency of the PSU but also on its noise level. Cybenetics Lambda certification levels include:

Standard — from 40 dB(A) to 45 dB(A) – noticeable noise;

Standard+ — from 35 dB(A) to 40 dB(A) – noticeable noise;

Standard++ — from 30 dB(A) to 35 dB(A) – moderate noise;

A- — from 25 dB(A) to 30 dB(A) – moderately quiet;

A — from 20 dB(A) to 25 dB(A) – quiet;

A+ — from 15 dB(A) to 20 dB(A) – very quiet;

A++ — less than 15 dB(A) – nearly silent.

The number of SATA power connectors provided in the PSU.

Nowadays, SATA is the standard interface for connecting internal hard drives, and it is also found in other types of drives (SSD, SSHD, etc.). Such an interface consists of a data connector connected to the motherboard, and a power connector connected to the PSU. Accordingly, in this paragraph we are talking about the number of SATA power plugs provided in the PSU. This number corresponds to the number of SATA drives that can be simultaneously powered from this model.

The presence of a braid in the complete wires of the system unit — for all or at least for some.

This feature has a positive effect on reliability, making the wire as resistant as possible to bending, abrasion, strong pressure and other similar influences; it also provides additional protection against accidental contact with sharp objects (for example, when repairing a PC). The disadvantages of braided wires, in addition to increased cost, are also increased thickness and greater rigidity than similar cables in conventional insulation. This can create some difficulties in organizing space inside the system unit.

Protection schemes provided in the power supply unit. In addition to the aforementioned OVP (Over Voltage Protection), OPP (Over Power Protection), and SCP (Short Circuit Protection), modern PSUs may include the following safety functions:

— OCP. OCP in power supplies monitors the current on power lines and shuts down the PSU if consumption becomes dangerously high, to prevent overheating wires, connectors, and power elements inside the unit, and to avoid affecting components. Unlike OPP, which triggers based on the total power of the whole unit, OCP often catches a localized issue on a specific line or group of outputs. Compared to SCP, it's an "earlier" protection: it reacts before a full short circuit forms when resistance is not zero but current is already risky. Real-life examples include an unsuccessful graphics card overclock, a damaged GPU power cable, or the rare but unpleasant case of connector bending/melting: OCP will shut down the unit faster than you'll notice the smell of plastic.

— UVP. UVP monitors the voltage drop on the power supply's outputs and shuts it down when the values become too low for stable operation to avoid freezes, data writing errors, and "half-dead" modes, which are especially unpleasant for the motherboard and drives. Paired with OVP, these protections work like "frames": OVP catches dangerous spikes, UVP catches dangerous drops, while SIP often tries to smooth out the power issue at the input. A typical ex...ample would be an overloaded weak PSU, poor grid, or turning on powerful appliances at home: instead of unstable operation and strange reboots, UVP prefers to shut down the system predictably.

— OTP. OTP monitors the temperature inside the power supply and shuts it down when the heat becomes critical, protecting the transformer, power switches, and capacitors from accelerated wear and accidents. This is a "harsher" safety net than AFC: automatic fan control tries to prevent overheating, while OTP kicks in when cooling no longer suffices— for example, if the case is clogged with dust, the fan stops, the PSU is in a cramped compartment, or the PC runs under heavy load for a long time in summer. In real life, OTP often saves the day when a user inadvertently blocks the air intake or the fan starts failing: instead of smoke and component degradation, the unit simply turns off.

— SIP. SIP in power supplies is designed for "dirty" power conditions: transient surges, drops, and inrush currents that occur when a fridge compressor, pump, or air conditioner starts up at home, or when the network is unstable. Conceptually, it aligns closer to smoothing out input problems than to OVP/UVP, which already monitor the output and simply shut down the PSU at dangerous values; SIP aims to enhance system resilience to everyday voltage drops and spikes but does not replace a full external stabilizer or robust power protection if the grid is truly bad. A typical example would be a private house or old housing stock: SIP helps endure minor network "nudges" without sudden reboots.

— NLO (No-Load Operation). The ability of a power supply to correctly start and operate even with zero or very low load on the outputs, without "floating" voltages and instability. Unlike protections like OVP/OCP/SCP that respond to emergencies (overvoltage, overload, short circuit) and often shut down the PSU, NLO focuses on stability when consumption is minimal, or the load is temporarily absent, reducing the risk of odd malfunctions during testing or in energy-saving scenarios. In practice, NLO is useful when testing the unit on a bench without a connected PC, when the system starts with a minimal set of components, and when the computer spends most of the time idling, reducing consumption to a "trivial" level.

— AFC. AFC in power supplies manages fan speed based on temperature and load: it rotates slower and quieter when idle, and speeds up as consumption increases to dissipate heat in time. This is not "emergency" protection like OTP, which shuts down the unit during overheating, but a preventative measure: AFC helps maintain temperature at a normal level, thereby indirectly prolonging the lifespan of PSU components. A real-life example is that at night, in a quiet room, the PC doesn't hum under low load, and during gaming, the cooling automatically intensifies, preventing OTP from triggering.

The noise level produced by the power supply.

Usually, the characteristics indicate the average value of the noise level during normal operation. The lower this value, the quieter the power supply and the more comfortable it is to use. However, it is worth noting that modern computer PSUs produce very little noise. So, in the quietest models, this figure does not exceed 20 dB — this is no louder than the rustling of leaves in a light breeze, such a sound is almost inaudible and is quite acceptable even in a residential area at night. Also acceptable for this application are noise sources of 21 – 25 dB(corresponding to a whisper at a distance of about 1 m) and 26 – 30 dB(wall clock ticking). Noise of more than 30 dB is already considered quite significant for computer PSUs; according to sanitary standards, such equipment in residential premises can only be used during the day.

When choosing a power supply for this indicator, it is worth considering a few points. First, noise reduction comes at a cost: it can affect the cooling performance and/or cost of the device. Secondly, the noise from the power supply is often lost against the background of louder PC components — for example, powerful cooling systems for the CPU or graphics card. Thirdly, the very environment where the PC is installed can be noisy — an example is a...n office or coworking. Thus, specifically looking for a low-noise model makes sense mainly in cases where maximum silence is crucial for you.

Manufacturer's warranty provided for this model.

In fact, this is the minimum service life promised by the manufacturer, subject to the rules of operation. There are both models with a small warranty up to 3 years, and more advanced power supplies, in which the warranty can reach 7, 10 years and even 12 years. In general , a 5-year warranty(for example) does not mean that the device will fail after the specified time. Most often, the actual service life of the device is much longer than the guaranteed one.

Specific warranty periods may vary even for similar drives from the same manufacturer. So not

PC PSU dimensions are defined by the form factor (most often ATX 150×86 mm), and the key factor in compatibility is depth — the PSU case length. “Universal” ATX units are usually 140, 150 mm, while quiet, high-power models with large heatsinks and a 135/140‑mm fan range from 160 to 200+ mm; compact builds use SFX/SFX-L (depth ~100 and ~125 mm with an adapter bracket). The greater the depth, the higher the risk of hitting drive cages, the PSU shroud, cable management, or a front LCS radiator, and modular connectors plus cable bend radius require another 20 – 40 mm of real clearance.