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Review of the Formula AP-500MM power supply

18.06.2024 10:50

We continue our series of reviews of power supplies with the lowest retail price, and this time we’ll look at the Formula AP-500MM power supply. In total, the manufacturer has eight models of this series available with power from 400 to 750 W.

Particular attention is drawn to the fact that a significant part of the body is made in the form of a mesh. This can be done both to increase aesthetic appeal and to save materials. In any case, part of the warm air removed by the power supply fan through its internals will be distributed inside the system unit and not removed outside. The Formula AP-500MM unit also dissipates heat well. The power supply housing is painted black, which, in combination with the packaging, emphasizes the orientation of this model towards the retail market. The dimensions of the power supply are standard, the length of the case is 140 mm.


All necessary parameters are clearly indicated on the power supply housing. The power on the +12VDC bus is 450 W, which is 90% of the total power of the unit. This means that most of the power is available at +12VDC, which is important for modern systems. However, it is worth considering that this is a budget solution on not the newest platform, and this is not its only limitation.

Wires and connectors

Connector nameNumber of connectorsNotes
24 pin Main Power Connector1collapsible
4 pin 12V Power Connector 
8 pin SSI Processor Connector1collapsible
6 pin PCI-E 1.0 VGA Power Connector 
8 pin PCI-E 2.0 VGA Power Connector2on one cord
4 pin Peripheral Connector2 
15 pin Serial ATA Connector6on two cords
4 pin Floppy Drive Connector- 

Length of wires to power connectors

  • 1 cord: to the main ATX connector — 50 cm
  • 1 cord: to the processor socket 8 pin SSI — 61 cm
  • 1 cord: to the first PCIe 2.0 VGA Power Connector video card power connector — 55 cm, plus another 15 cm to the second same connector
  • 2 cords: to the first SATA Power Connector — 45 cm, plus 15 cm to the second and another 15 cm to the third similar connector, plus another 15 cm to the Peripheral Connector (Molex)

The length of the wires in this power supply model is not the greatest, however, in modern medium-sized cases and with a hidden wiring system, there are no problems with assembly.

All wires are rigidly fixed, which is typical for budget solutions. In any case, their number is limited, which corresponds to the maximum power and indicates incompatibility with the assembly of high-performance systems.

SATA connectors are straight, which is convenient for connecting drives to the back of the motherboard base or other surfaces.

However, the distribution of connectors along the power cords may not be the most convenient for simultaneously connecting multiple devices at long distances from the power supply. In a typical system with a small number of drives this is not a problem, but in a mini PC it may require more careful planning.

It is worth noting the use of ribbon wires, which improves the ease of assembly and subsequent operation.

Overall, from a wiring perspective, this model offers ease of assembly, making it competitive with similar models.

Circuit design and cooling

The power supply is equipped with an active power factor correction, but has a standard rather than extended range of supply voltages.

The main semiconductor elements are placed on two small radiators. The first radiator houses the elements of the power factor corrector and the main AC inverter, and the second one houses the rectifiers.

The platform here is not the most advanced: it uses group stabilization of the +5VDC and +12VDC channels, as well as +3.3VDC on a separate stabilizer based on a magnetic amplifier. This is typical for low-budget solutions.

A Nichicon capacitor with a capacity of 220 µF is installed at the input. The remaining low voltage circuits are dominated by capacitors from ChengX.

The power supply contains a Xiongli Electronic W12025HZ12SEMA fan with a diameter of 120 mm. The PSU manufacturer claims that the fan is equipped with a hydrodynamic bearing. The fan connection is two-wire and detachable, which makes it easy to replace and also ensures trouble-free operation during the warranty period.

Electrical Characteristics Measurement

Next, we move on to analyzing the electrical characteristics of the power source using a multifunctional stand and other equipment.

The amount of deviation of the output voltages from the nominal value will be represented by color coding as follows:

Operating at maximum power

The first stage of testing is to operate the power supply at maximum power for an extended period of time. This test allows you to verify the reliability of the power supply. In this case, we carried out the tests several times to avoid possible problems with overheating of the connectors due to their limited number.

The power supply is indeed capable of operating at the maximum declared power for a long time, however, in a real system it will be difficult to achieve this power due to the limited number of power connectors for video cards and the inability to significantly load the +3.3VDC and +5VDC channels.

Cross-load characteristic

KNKh allows you to determine what load level can be considered acceptable for the tested specimen, especially on the +12VDC channel. In this case, deviations of the effective voltage values ​​from the nominal value on the +12VDC channel exceed 3% with a load power of over 400 W. Deviations along the +5VDC channel are about 5% towards increasing values.

This behavior is often found in power supplies with group stabilization, but this model is no exception.

A study was carried out on the +5VDC channel, from which it follows that with a load of up to 230 W on the +12VDC channel, the deviation on the +5VDC channel does not exceed 4% of the nominal value. This deviation is observed with a typical load on the +3.3VDC and +5VDC channels, characteristic of modern systems.

Load capacity

The following test is aimed at determining the maximum power that can be transmitted through the corresponding connectors when the voltage tolerance is within 3% or 5% of the nominal voltage.

In the case of a video card with a single power connector, the maximum power over the +12VDC channel is at least 150 W with a deviation within 3%.

In the case of a video card with two power connectors, the maximum power via the +12VDC channel is at least 250 W with a permissible deviation within 3%. Medium-power video cards with this power supply should work without any problems.

When loaded through the processor power connector, the maximum power through the +12VDC channel is at least 250 W with a permissible deviation within 3%. For budget systems this is enough.

In the case of a motherboard, the maximum power on the +12VDC channel is at least 150 W with a permissible deviation within 3%. Considering that the board itself consumes about 10 W through this channel, high power may be required to power expansion cards, for example, video cards without an additional power connector, which usually have a consumption of around 75 W.

Cost-effective and efficient

When assessing the efficiency of a computer power supply, you can approach it in two ways. The first approach is to consider the power supply as a separate device that converts electrical energy while minimizing losses along the transmission line to the load. To do this, the power supply is connected with all available connectors, which creates unequal conditions for different models, taking into account different sets of connectors and numbers of current-carrying wires.

However, in real-world applications, the power supply is usually connected through only a limited number of connectors, which makes the data obtained of little use for understanding its real efficiency. Therefore, a more logical approach to assessing the efficiency (cost-effectiveness) of a computer power supply is to use fixed power values ​​and power distribution across channels, taking into account a specific set of connectors for each model.

Efficiency ratings are often expressed in terms of coefficient of performance (COP), which reflects the ratio of the power supply's output power to its input power. For the average user, this parameter is not always clear, but it has become an important element of the marketing strategy, especially with 80Plus certification. In practical terms, high efficiency does not affect the performance or other characteristics of the system unit, but only indicates the efficiency and quality of the device.

On the other hand, to objectively assess the efficiency of a power supply, it is important to take into account the power dissipation, which is the difference between the input and output powers of the unit. This allows you to calculate actual energy consumption and assess the economic feasibility of using a specific power supply model over a long period of time.

Thus, the methodology for measuring power supply efficiency must be adapted to real-world usage conditions, taking into account the specific characteristics of the connectors and the power available for each model.

Load through connectors12VDC, W5VDC, W3.3VDC, WTotal power, W
main ATX, processor (12 V), SATA55515
main ATX, processor (12 V), SATA80155100
main ATX, processor (12 V), SATA180155200
Main ATX, CPU (12V), 6-pin PCIe, SATA380155400
Main ATX, CPU (12V), 6-pin PCIe (1 cord with 2 connectors), SATA480155500
main ATX, processor (12 V), 6-pin PCIe (2 cords per 1 connector), SATA480155500
Main ATX, CPU (12 V), 6-pin PCIe (2 cords x 2 connectors), SATA730155750

The results obtained look like this:

Power dissipation, W15 W100 W200 W400 W500 W
(1 cord)
500 W
(2 cords)
750 W
Cougar BXM 70012. 
Cooler Master Elite 600 V411.417.830.165.793.0  
Cougar GEX 85011.814.520.632.641.040.572.5
Cooler Master V650 SFX7.813.819.633.042.441.4 
Chieftec BDF-650C13.019.027.635.569.867.3 
XPG Core Reactor 7508.014.318.530.741.840.472.5
Deepcool DQ650-M-V2L11.013.819.534.744.0  
Deepcool DA600-M13.619.830.061.386.0  
Fractal Design Ion Gold 85014.917.521.537.247.445.280.2
XPG Pylon 75011.115.421.741.057.056.7111.0
Chieftronic PowerUp GPX-850FC12.815.921.433.239.438.269.3
MSI MPG A750GF11.515.721.030.639.238.069.0
Chieftronic PowerPlay GPU-850FC12.015.919.728.134.033.356.0
Cooler Master MWE Gold 750 V212.
XPG Pylon 45012.618.528.463.0   
Chieftronic PowerUp GPX-550FC12.215.421.635.7 47.1 
Chieftec BBS-500S13.316.322.238.6   
Cougar VTE X2 60013.318.328.049.364.2  
Thermaltake GX1 50012.814.119.534.847.6  
Thermaltake BM2 45012.216.726.357.9   
Super Flower SF-750P14XE14.016.523.
XPG Core Reactor 8509.814.918.129.038.437.063.0
Asus TUF Gaming 750B11.113.820.738.650.749.393.0
Chieftronic BDK-650FC12.614.320.441.153.550.6 
Cooler Master XG Plus 750 Platinum13.814.218.936.543.040.061.1
Chieftec GPC-700S15.621.430.963.584.0  
Zalman ZM700-TXIIv212.519.530.862.083.080.0 
Cooler Master V850 Platinum17.820.124.634.538.337.858.5
Chieftec CSN-650C10.712.517.532.0 43.5 
Powerman PM-300TFX12.020.038.2    
Chieftec GPA-700S13.419.330.364.186.5  
XPG Probe 600W12.819.629.558.080.0  
Super Flower Leadex VII XG 850W11.714.518.426.7 32.2 
Cooler Master V850 Gold i Multi10.814.619.832.0 37.0 
Cooler Master V850 Gold V2 WE11.313.617.
Cooler Master MWE 750 Bronze V218.019.323.241.853.454.299.1
Chieftec EON 600W (ZPU-600S)13.119.831.563.589.0  
Formula AP-500MM12.319.331.666.5   

This model has low efficiency in all tested modes; it is a completely typical representative of power supplies in the budget segment, which are not chosen for efficiency.

In terms of power dissipation when operating at a low load (and this model cannot handle a high load), the Formula AP-500MM takes an honorable second-to-last place in the list of power supplies up to a kilowatt.

Computer energy consumption per year, kWh15 W100 W200 W400 W500 W
(1 cord)
500 W
(2 cords)
750 W
Cougar BXM 70023710351980387948834880 
Cooler Master Elite 600 V42311032201640805195  
Cougar GEX 850235100319333790473947357205
Cooler Master V650 SFX2009971924379347514743 
Chieftec BDF-650C24510421994381549914970 
XPG Core Reactor 750202100119143773474647347205
Deepcool DQ650-M-V2L228997192338084765  
Deepcool DA600-M2511049201540415133  
Fractal Design Ion Gold 850262102919403830479547767273
XPG Pylon 750229101119423863487948777542
Chieftronic PowerUp GPX-850FC244101519403795472547157177
MSI MPG A750GF232101419363772472347137174
Chieftronic PowerPlay GPU-850FC237101519253750467846727061
Cooler Master MWE Gold 750 V2238101619363807474847447239
XPG Pylon 450242103820014056   
Chieftronic PowerUp GPX-550FC238101119413817 4793 
Chieftec BBS-500S248101919473842   
Cougar VTE X2 6002481036199739364942  
Thermaltake GX1 5002441000192338094797  
Thermaltake BM2 450238102219824011   
Super Flower SF-750P14XE254102119543811474847657236
XPG Core Reactor 850217100719113758471647047122
Asus TUF Gaming 750B22999719333842482448127385
Chieftronic BDK-650FC24210011931386448494823 
Cooler Master XG Plus 750 Platinum252100019183824475747307105
Chieftec GPC-700S2681064202340605116  
Zalman ZM700-TXIIv224110472022404751075081 
Cooler Master V850 Platinum287105219683806471647117083
Chieftec CSN-650C22598619053784 4761 
Powerman PM-300TFX23710512087    
Chieftec GPA-700S2491045201740665138  
XPG Probe 600W2441048201040125081  
Super Flower Leadex VII XG 850W234100319133738 4662 
Cooler Master V850 Gold i Multi226100419253784 4704 
Cooler Master V850 Gold V2 WE23099519033758469746927118
Cooler Master MWE 750 Bronze V2289104519553870484848557438
Chieftec EON 600W (ZPU-600S)2461049202840605160  
Formula AP-500MM239104520294087   


In this case, the thermal load of the capacitors remains at a low level throughout the entire power range, which is a positive aspect. This fact is explained not so much by high efficiency or high-quality design, but by the presence of a high-speed fan and many holes on different sides of the power supply case. Thanks to this, it was possible to effectively organize heat removal, including its distribution inside the system unit case.

Acoustic ergonomics

To measure the noise level of power supplies, we used the following method. The power supply was placed on a flat surface with the fan facing upwards. At a distance of 0.35 meters from the block, a measuring microphone of the Oktava 110A-Eco sound level meter was installed to carry out measurements. The load on the power supply was carried out using a special stand that ensured silent operation. The power supply operated at constant power for 20 minutes, after which the noise level was measured.

This distance to the noise source is the closest to the situation where the system unit is placed on a desktop with the power supply installed. This method allows you to accurately estimate the noise level of the power supply in conditions where the user is close to the noise source. As the distance to the block increases and additional obstacles appear that reflect sound well, the noise level at the measuring point will also decrease, which helps to increase acoustic comfort in general.

When measuring the noise level of power supplies, we used the following approach. The power supply was placed on a flat surface with the fan facing upward. At a distance of 0.35 meters from it, an Octava 110A-Eco sound level meter was located to measure the noise level. The load on the power supply was carried out by a special stand that ensured silent operation. The power supply was operated at constant power for 20 minutes, after which the noise level was measured.

This method allows you to accurately determine the noise level of the power supply when it is located on a table in the near field from the user. As the distance to the block increases and barriers are used, the noise level at the measurement point also decreases, improving overall acoustic comfort.

Consumer qualities

The acoustic ergonomics of this power supply, one might say, do not stand out particularly, which is typical for its price category. However, at a power below 300 W, the noise remains at a level that is quite comfortable for most users. It is recommended to consider purchasing this power supply for systems whose consumption does not exceed 250-300 W. The +12VDC channel has sufficient load capacity, which is especially important for video adapters. The only potential problem may arise with the +5VDC channel due to long wires and less than optimal connectors. In general, the consumer qualities of this model can be considered satisfactory, especially considering its budget nature.


The Formula AP-500MM power supply is fully suitable for powering an entry-level system unit with a total power of up to 300 W (and also higher if you don’t mind listening to the fan). In typical modes, it shows adequate parameters and works successfully for a long time at high loads, which is a positive aspect. However, keep in mind that this is a budget product with its own features and limitations.