In the second part of our mainstream power supply test, we compare seven additional units with a maximum power of 700 watts. To enable an easier comparison, the units from the first part have been included in the charts for this piece as well.
The new candidates in the comparison are as follows :
| Manufacturer | Power Supply Model |
|---|---|
| Corsair | HX520W |
| Enermax | Modu 82+ 525W |
| Fortron/FSP | Everest 80Plus 600 |
| Hiper | Type R MK II 680 |
| PC Power & Cooling | Silencer 610W |
| Silver Power | SP-SS500 |
| Tagan | TG680-U33II |
And of course, the power supplies already tested in the previous part :
| Manufacturer | Power supply |
|---|---|
| Antec | Signature |
| Cooler Master | Silent Pro 500 W |
| Dragon Force | DF-530GT |
| Silverstone | SST-ST70F Strider |
| Thermaltake | Toughpower QFan 650W |
On to the first model, Enermax’s Modu 82+...
Enermax is jumping onto the energy-savings train, and has entered its 525 watt Modu82+ model into the race. The marketing name is designed to suggest greater efficiency to the customer: the reference to the 80Plus standard is surely not coincidental, and the Modu82+ does have this certification. But there is no 82Plus standard.
As the name suggests, this is a power supply with modular connection cables. The ATX connections and the CPU power are attached directly to the power supply. The sockets for PCIe as well as Molex and SATA are different, unlike the previous models we’ve seen, and cannot be confused. The connection cables are not compatible with the company’s older products.
The cooling of the power supply is handled by a 120 mm fan, with speed automatically regulated based on temperature. There is no manual setting, so you’ll have to trust that Enermax’s balance between noise and heat is acceptable The fan follow-up control used to protect the components, which you may have been familiar with from Enermax’s previous series is no longer included with the Modu82+.

Enermax makes a sufficient number of SATA and Molex connections available, but the gaps between the connections are very small. This may lead to trouble with installing drives that require more clearance.
Enermax is the only manufacturer to have added a cable with a speed indicator for the fan. This enables the user to keep an eye on the power supply fan using monitoring software—a welcome addition for enthusiasts.
As we’ve come to expect with an Enermax modular power supply, a bag is included for the connection cables. Four additional cable ties with hook and eye fastenings ensure a nice, neat system build.
| Nominal Value | Measurement | Permitted Deviation |
|---|---|---|
| 3.3 V | 3.22 V | 3.14 V to 3.47 V |
| 5 V | 5.02 V | 4.75 V to 5.25 V |
| 12 V | 12.22 V | 11.40 V to 12.60 V |
| 12 V (CPU) | 12.06 V | 11.40 V to 12.60 V |
| 5 V (Standby) | 5.09 V | 4.75 V to 5.25 V |
| -12 V | -12.08 V | -10.80 V to -13.20 V |
| Nominal Value | Measurement | Permitted Deviation |
|---|---|---|
| 3.3 V | 3.27 V | 3.14 V to 3.47 V |
| 5 V | 5.08 V | 4.75 V to 5.25 V |
| 12 V | 12.22 V | 11.40 V to 12.60 V |
| 12 V (CPU) | 12.18 V | 11.40 V to 12.60 V |
| 5 V (Standby) | 5.10 V | 4.75 V to 5.25 V |
| -12 V | -11.78 V | -10.80 V to -13.20 V |
| Nominal Value | Measurement | Permitted Deviation |
|---|---|---|
| 3.3 V | 3.32 V | 3.14 V to 3.47 V |
| 5 V | 5.10 V | 4.75 V to 5.25 V |
| 12 V | 12.27 V | 11.40 V to 12.60 V |
| 12 V (CPU) | 12.26 V | 11.40 V to 12.60 V |
| 5 V (Standby) | 5.14 V | 4.75 V to 5.25 V |
| -12 V | -11.64 V | -10.80 V to -13.20 V |

The efficiency at medium load is surprisingly good, at almost 87%, but this drops considerably at maximum and low loads. In both of these cases, it only reaches 84%. However, the "Modu 82+" name is justified even here, as the efficiency is constantly above that figure. For what it’s worth, that’s good enough to qualify the supply for the 80Plus Bronze certification, if Enermax pursued it.
This model has some difficulty in our Low Power Test with a low load of 35 watts. Here it barely reaches 72%. The standby energy expenditure lies at 600 mW which is very low. With load, the power supply consumes 4.35 watts, which is average.
The 525 watt version of the Enermax Modu 82+ is available for a price of around $140.
- Positive
- Negative
- High efficiency under partial loads
- Low standby consumption
- Confusing “82+” specification in the product name
Hiper sent us the MK2, the second generation of its Type R power supplies to take part in our test. Unlike the earlier models, the one is no longer fitted with modular connection cables; the attractive metal screw connectors are a thing of the past. But it is still sold in the traditional manner, in a practical plastic box. With its reflective surfaces and perforated sheets, the power supply makes a good visual impression.
A highlight here is the USB ports on the power supply. These effectively make the power supply a USB hub as well, so it is able to supply a full 500 mA of current to any USB port. For the USB ports on the motherboard, this power is limited to a single root hub. The USB data cables, on the other hand, are connected through to the motherboard. An additional USB port is available as a power supply-only (without the data function) and can supply up to 1 A current, making it ideal for charging a cell phone or connecting USB mug warmers or other passive "USB toys."
Technically, the power supply is very impressive, with all voltages constantly within tolerances. Hiper has clearly learned from its past mistakes.

The power supply can only really be considered "partially modular," as the manufacturer has only supplied short adapter cables, called Xtenders. This means that it is possible to enable neat cable management, without the classic modular cables.
The connection cable, on the other hand, is modular. The manufacturer has included a modular IEC cable with German and English style power plugs to save weight.
As a nice bonus, the power supply packaging can be used as a box for small parts in the workshop or the garage.
| Nominal Value | Measurement | Permitted Deviation |
|---|---|---|
| 3.3 V | 3.23 V | 3.14 V to 3.47 V |
| 5 V | 4.99 V | 4.75 V to 5.25 V |
| 12 V | 11.98 V | 11.40 V to 12.60 V |
| 12 V (CPU) | 11.78 V | 11.40 V to 12.60 V |
| 5 V (Standby) | 5.05 V | 4.75 V to 5.25 V |
| -12 V | -12.34 V | -10.80 V to -13.20 V |
| Nominal Value | Measurement | Permitted Deviation |
|---|---|---|
| 3.3 V | 3.30 V | 3.14 V to 3.47 V |
| 5 V | 5.05 V | 4.75 V to 5.25 V |
| 12 V | 12.05 V | 11.40 V to 12.60 V |
| 12 V (CPU) | 11.95 V | 11.40 V to 12.60 V |
| 5 V (Standby) | 5.10 V | 4.75 V to 5.25 V |
| -12 V | -12.15 V | -10.80 V to -13.20 V |
| Nominal Value | Measurement | Permitted Deviation |
|---|---|---|
| 3.3 V | 3.34 V | 3.14 V to 3.47 V |
| 5 V | 5.08 V | 4.75 V to 5.25 V |
| 12 V | 12.09 V | 11.40 V to 12.60 V |
| 12 V (CPU) | 12.08 V | 11.40 V to 12.60 V |
| 5 V (Standby) | 5.13 V | 4.75 V to 5.25 V |
| -12 V | -12.01 V | -10.80 V to -13.20 V |

The Hiper achieves a good efficiency level at half load of 87%, while under full load it is a respectable 85%. If the load is reduced, the level of efficiency also drops. At low load, it is a slim 83.5%, while at a load of 250 watts it is still 84%. The efficiency becomes poor when it comes to our Low Power Test: 65% is not as good as we’d like to see here.
In standby mode, the energy consumption is relatively high. Without load, the power supply draws 1.63 watts from the main power source, and with a load of 2.50 watts, the power supply draws some 5.93 watts. This high consumption is probably a result of the integrated USB hub.
The 680 W Type R MK II watts can be purchased for around $150.
- Positive
- Negative
- Integrated USB hub
- Additional USB power supply
- High efficiency under full and partial loads
- Low efficiency in standby
The Tagan SuperRock TG680-U33II has a maximum performance of 680 watts. Conspicuous on this model is the LED on the rear of the power supply, which shows the operating status: green means that the unit is operating, while orange tells you that it is in standby mode. The power supply is fitted with a 120 mm fan, which is located on the underside and regulated automatically.

The manufacturer has chosen not to fit the power supply with modular connection cables. Cables and connectors are available in suitable quantities, though: 6x SATA, 6x Molex, 1x PCIe, 1x PCIe 6/8, and 1x P4/P8.
The cables have a plastic braided coating along their entire length, which makes them very stiff at the connectors.
One positive is the different colors used for PCIe and P4/P8 connectors, which prevents confusion.
| Nominal Value | Measurement | Permitted Deviation |
|---|---|---|
| 3.3 V | 3.25 V | 3.14 V to 3.47 V |
| 5 V | 4.98 V | 4.75 V to 5.25 V |
| 12 V | 11.96 V | 11.40 V to 12.60 V |
| 12 V (CPU) | 11.80 V | 11.40 V to 12.60 V |
| 5 V (Standby) | 4.93 V | 4.75 V to 5.25 V |
| -12 V | -12.08 V | -10.80 V to -13.20 V |
| Nominal Value | Measurement | Permitted Deviation |
|---|---|---|
| 3.3 V | 3.33 V | 3.14 V to 3.47 V |
| 5 V | 5.04 V | 4.75 V to 5.25 V |
| 12 V | 12.06 V | 11.40 V to 12.60 V |
| 12 V (CPU) | 12.02 V | 11.40 V to 12.60 V |
| 5 V (Standby) | 4.99 V | 4.75 V to 5.25 V |
| -12 V | -11.78 V | -10.80 V to -13.20 V |
| Nominal Value | Measurement | Permitted Deviation |
|---|---|---|
| 3.3 V | 3.37 V | 3.14 V to 3.47 V |
| 5 V | 5.07 V | 4.75 V to 5.25 V |
| 12 V | 12.13 V | 11.40 V to 12.60 V |
| 12 V (CPU) | 12.10 V | 11.40 V to 12.60 V |
| 5 V (Standby) | 5.03 V | 4.75 V to 5.25 V |
| -12 V | -11.59 V | -10.80 V to -13.20 V |

The Tagan power supply has a very high level of efficiency, not dropping below 85%. The highest value of 88% is achieved at medium load. Only when the load is very low—our fictitious Low Power System with a 35 watt loss—does the efficiency drop below 65%.
The Tagan unit does not do so well in standby mode, though. Without load, the power supply draws 1.58 watts from the power source, and if the power supply is loaded with 500 mA on the standby rail, it takes 4.70 watts. Here, the efficiency is barely over 50%.
Unfortunately, the SuperRock appears to be one of those products that is enjoying plenty of popularity overseas, but isn’t yet available to North American customers.
- Positive
- Negative
- High efficiency under load
- Non-modular design
- Low efficiency in standby mode
Fortron has given its new 600 W Everest power supply the name "80 Plus", probably to ensure that it is found when customers search for this term. It lives up to this name, and has the appropriate certification (as do many of its competitors). As is usually the case for Fortron retail products, the power supply is blue in color.
The Everest is modular; only the ATX connector, one PCIe line and the P4 and P8 connectors are permanently fixed to the power supply. Aside from these, there are three ports for SATA and Molex cables, as well as two for additional PCIe cables. For the latter, the cable coatings and the ports are both also blue in color.
Fortron advertises its Everest power supply with a special function: at a load of up to 20% (120 watts) the power supply functions silently. This can be seen as soon as the unit is switched on. The fan starts up for a brief moment and then stops again immediately. Interestingly, the operating instructions don’t make any mention of this feature, which could cause the more easily spooked user to assume a fault. After all, even when under full load, the fan only starts up after a time.

The power supply may be completely without noise at low loads, but when it reaches the switch-on threshold, the fan is clocked at such a low speed that it makes a creaking noise. This is very disturbing in the range between 110 and 250 watts. The temperature in the power supply increases, the fan starts to rotate with a creak and cools the temperature down, it stops, and then starts up again less than two minutes later. If the user isn’t constantly working in either an extremely low performance or an extremely high performance range, he or she will soon be rather annoyed with the power supply turning the fan off and on.
Our measurements also found that fan-less operation at a full 20% load is not possible. The threshold in the Tom’s Hardware lab with an ambient temperature of about 25 °C lies at about 100 watts.
An interesting detail is the blue lit power switch: this becomes brighter when the unit is switched on than it is when in standby. If the power supply is switched off completely, it is not lit at all.
| Nominal Value | Measurement | Permitted Deviation |
|---|---|---|
| 3.3 V | 3.22 V | 3.14 V to 3.47 V |
| 5 V | 4.92 V | 4.75 V to 5.25 V |
| 12 V | 12.02 V | 11.40 V to 12.60 V |
| 12 V (CPU) | 11.97 V | 11.40 V to 12.60 V |
| 5 V (Standby) | 4.97 V | 4.75 V to 5.25 V |
| -12 V | -12.24 V | -10.80 V to -13.20 V |
| Nominal Value | Measurement | Permitted Deviation |
|---|---|---|
| 3.3 V | 3.28 V | 3.14 V to 3.47 V |
| 5 V | 5.04 V | 4.75 V to 5.25 V |
| 12 V | 12.06 V | 11.40 V to 12.60 V |
| 12 V (CPU) | 12.04 V | 11.40 V to 12.60 V |
| 5 V (Standby) | 5.04 V | 4.75 V to 5.25 V |
| -12 V | -12.04 V | -10.80 V to -13.20 V |
| Nominal Value | Measurement | Permitted Deviation |
|---|---|---|
| 3.3 V | 3.32 V | 3.14 V to 3.47 V |
| 5 V | 5.11 V | 4.75 V to 5.25 V |
| 12 V | 12.07 V | 11.40 V to 12.60 V |
| 12 V (CPU) | 12.06 V | 11.40 V to 12.60 V |
| 5 V (Standby) | 5.08 V | 4.75 V to 5.25 V |
| -12 V | -11.88 V | -10.80 V to -13.20 V |

The efficiency of the power supply is very good with a partial load. It achieves a level of 88% at 50% load and almost 86% at 20% load. The power supply also does well in the 35 watt test, where it still reaches 74.4%. Under full load, the power supply reaches 85.6% which is still a good level of efficiency.
The power supply doesn’t achieve particularly special results in standby mode. A power consumption of 4.41 watts results in a level of efficiency of just 56.6%. Without load, consumption is pretty low at 0.61 watts.
Incidentally, the difference in energy consumption with the fan on or off is just 0.5 watts.
- Positive
- Negative
- Silent at very low loads
- High efficiency
- Passive operation is not possible at 20% load
- Power supply is much too loud when switching the fan on
PC Power & Cooling takes quiet operation seriously, or at least one would assume so based on the name "Silencer" given to its 610 watt power supply. As soon as it is switched on, though, we had to take issue a bit with that word. Although the fan doesn’t turn all that quickly, it hums rather disturbingly. On the plus side, at higher loads, the noise from the power supply does not increase very much.
This power supply is one of the few units to employ a classical construction with a 80 mm fan and airflow from front to back through the housing. This means it can be used in server housings and small home theater PCs.
Other details also remind us of a server power supply. The black and relatively heavy power supply has no frills and the connection cables are not modular. We know from experience that the folks at PC Power and Cooling consider modularity a liability, since each connected cable is just another possible failure point as the supply ages.
A supplied test protocol from the Taiwanese company "Fast Auto Electronic" informs the purchaser of the tests carried out, including a test with maximum load on the individual voltage rails. The FA-4200ATE test device was used for the tests.
PC Power & Cooling is one of the few manufacturers to use a single rail voltage supply on the 12 volt rail, which can be loaded with 49 Amperes.

The SATA and Molex connectors are available in suitable quantities. The cables with the Molex connectors are of varying lengths, which is very practical when dealing with large tower housings.
Two blue caps can be slipped onto the redundant Molex connectors to prevent short-circuiting due to contact with electronic components or the housing. These caps are not available for SATA or other connectors though, given the much safer design of those interfaces.
| Nominal Value | Measurement | Permitted Deviation |
|---|---|---|
| 3.3 V | 3.24 V | 3.14 V to 3.47 V |
| 5 V | 4.84 V | 4.75 V to 5.25 V |
| 12 V | 11.95 V | 11.40 V to 12.60 V |
| 12 V (CPU) | 11.81 V | 11.40 V to 12.60 V |
| 5 V (Standby) | 4.89 V | 4.75 V to 5.25 V |
| -12 V | -12.19 V | -10.80 V to -13.20 V |
| Nominal Value | Measurement | Permitted Deviation |
|---|---|---|
| 3.3 V | 3.32 V | 3.14 V to 3.47 V |
| 5 V | 4.91 V | 4.75 V to 5.25 V |
| 12 V | 12.03 V | 11.40 V to 12.60 V |
| 12 V (CPU) | 12.00 V | 11.40 V to 12.60 V |
| 5 V (Standby) | 4.93 V | 4.75 V to 5.25 V |
| -12 V | -11.92 V | -10.80 V to -13.20 V |
| Nominal Value | Measurement | Permitted Deviation |
|---|---|---|
| 3.3 V | 3.36 V | 3.14 V to 3.47 V |
| 5 V | 4.96 V | 4.75 V to 5.25 V |
| 12 V | 12.07 V | 11.40 V to 12.60 V |
| 12 V (CPU) | 12.06 V | 11.40 V to 12.60 V |
| 5 V (Standby) | 4.95 V | 4.75 V to 5.25 V |
| -12 V | -11.74 V | -10.80 V to -13.20 V |

As far as efficiency is concerned, the power supply from PC Power & Cooling is not able to produce the best results in our roundup. The maximum efficiency reached by the unit is at a 50 percent load, where it hits 86%. If the load is increased or decreased, the efficiency drops considerably, though; in the low load range (20%) it is just 83%, while under full load, the unit achieves 84%.
In standby, though, the efficiency of the power supply achieves top marks: under a standby load of 0.5 A, the unit draws 3.73 watts, which corresponds to a level of efficiency of 67%. Without load, the power consumption is less than one watt. Here, the unit draws 0.72 watts from the power source.
Fortunately, the Silencer is widely available in North America and is available online for just less than $100, making it a reasonable value.
- Positive
- Negative
- Good standby efficiency
- Classical fan design for servers and HTPCs
- Humming fan
The 500 W SP-SS500 from Silver Power is one of the few units to not have cable management. The connection cables are coated along their full length, which means that they are somewhat stiff at the drive connectors, with the exception of the SATA cables.
The power supply is relatively quiet at low and medium loads, but when put under high load, the 120 mm fan rotates quickly and the power supply becomes rather loud. The voltages are very stable, and do not change even under high load.

Peripheral connections are available in sufficient quality (6x SATA and 6x Molex), but the gaps between the individual connectors are very small, which may cause problems when it comes to connecting numerous devices. The SATA connection cables and the Molex cables are all of differing lengths. Along with a purely PCIe connection employing 6 pins, there is also an divisible connector with either 8 or 6 pins.
| Nominal Value | Measurement | Permitted Deviation |
|---|---|---|
| 3.3 V | 3.25 V | 3.14 V to 3.47 V |
| 5 V | 4.81 V | 4.75 V to 5.25 V |
| 12 V | 12.08 V | 11.40 V to 12.60 V |
| 12 V (CPU) | 11.98 V | 11.40 V to 12.60 V |
| 5 V (Standby) | 4.92 V | 4.75 V to 5.25 V |
| -12 V | -11.68 V | -10.80 V to -13.20 V |
| Nominal Value | Measurement | Permitted Deviation |
|---|---|---|
| 3.3 V | 3.29 V | 3.14 V to 3.47 V |
| 5 V | 4.92 V | 4.75 V to 5.25 V |
| 12 V | 12.07 V | 11.40 V to 12.60 V |
| 12 V (CPU) | 12.05 V | 11.40 V to 12.60 V |
| 5 V (Standby) | 4.96 V | 4.75 V to 5.25 V |
| -12 V | -11.37 V | -10.80 V to -13.20 V |
| Nominal Value | Measurement | Permitted Deviation |
|---|---|---|
| 3.3 V | 3.33 V | 3.14 V to 3.47 V |
| 5 V | 4.98 V | 4.75 V to 5.25 V |
| 12 V | 12.07 V | 11.40 V to 12.60 V |
| 12 V (CPU) | 12.06 V | 11.40 V to 12.60 V |
| 5 V (Standby) | 4.98 V | 4.75 V to 5.25 V |
| -12 V | -11.16 V | -10.80 V to -13.20 V |

The efficiency of the Silver Power supply is refreshingly high at 87% for medium loads, and remains at 86% even at low loads. Only under full load does the efficiency sink to 84%.
In our 35 watt test, the power supply achieves 75% efficiency, which is still a comparatively high level.
The low load in standby is worthy of note here; the Silver Power supply only uses 0.43 watts and thus has the lowest power consumption of the entire test field. Also, with load on standby of 500 mA, the Silver Power power supply is the most efficient, with a power consumption of 3.70 watts. This puts it at the top of the field (even if only by a small margin).
Yet again, however, we find this supply available overseas without much availability in the US.
- Positive
- Negative
- High efficiency
- Very loud under high load
The Corsair HX520W is something of a veteran among power supplies ; the product has been on the market for quite some time now. This unit is a modular power supply with an output level of 520 watts.
The power supply has a 120 mm fan which is very quiet when running, even under high loads. Conventional cables permanently affixed to the power supply are used for both the CPU supply and the ATX connections.
The labeling of the power supply on the rear is very informative, allowing you to determine the characteristics of the supply without needing to open up the case. Other manufacturers should take a page from Corsair here.

Flat, flexible cables are used as the modular cables, similar to the Cooler Master Silent Pro series; they have the advantage of being very easy to install in the housing. It is just as easy to form tight rings at the graphics card, as it is to form small loops at closely fitted drives, and unneeded cables can be stored in the supplied cable bag. The connections for the floppy drive are implemented via an adapter connection.
| Nominal Value | Measurement | Permitted Deviation |
|---|---|---|
| 3.3 V | 3.26 V | 3.14 V to 3.47 V |
| 5 V | 4.86 V | 4.75 V to 5.25 V |
| 12 V | 11.89 V | 11.40 V to 12.60 V |
| 12 V (CPU) | 11.88 V | 11.40 V to 12.60 V |
| 5 V (Standby) | 4.92 V | 4.75 V to 5.25 V |
| -12 V | -12.22 V | -10.80 V to -13.20 V |
| Nominal Value | Measurement | Permitted Deviation |
|---|---|---|
| 3.3 V | 3.33 V | 3.14 V to 3.47 V |
| 5 V | 4.93 V | 4.75 V to 5.25 V |
| 12 V | 12.07 V | 11.40 V to 12.60 V |
| 12 V (CPU) | 12.04 V | 11.40 V to 12.60 V |
| 5 V (Standby) | 4.96 V | 4.75 V to 5.25 V |
| -12 V | -11.97 V | -10.80 V to -13.20 V |
| Nominal Value | Measurement | Permitted Deviation |
|---|---|---|
| 3.3 V | 3.37 V | 3.14 V to 3.47 V |
| 5 V | 4.97 V | 4.75 V to 5.25 V |
| 12 V | 12.11 V | 11.40 V to 12.60 V |
| 12 V (CPU) | 12.10 V | 11.40 V to 12.60 V |
| 5 V (Standby) | 4.98 V | 4.75 V to 5.25 V |
| -12 V | -11.80 V | -10.80 V to -13.20 V |

The maximum level of efficiency for this model is achieved at half of the maximum load, where we measured 86%. Under full load, the value drops to about 84.5%, while at low loads (20%), the power supply achieves a comparatively low efficiency of 82.4%—the lowest in our test field. Here, we need to take into account the fact that the design of this power supply unit is older than that of the other models.
In testing with our 35 watt PC, the efficiency sunk to 67.9%, but in comparison with the competition, that was not a bad result.
The standby consumption of 0.70 watts with no load is respectable, and even with load on the standby cable, the unit still does alright. A power consumption of 3.93 watts with a load of 2.5 watts is good when compared to the competition.
The Corsair HX520W can be purchased from retailers at a price of around $120. And because it comes from Corsair, local availability is plentiful.
- Positive
- Negative
- High efficiency at full load
- Quiet
- Good modular cables
- Low efficiency under low loads






Our editorial team’s recommendation is the Type R MKII 680 from Hiper. It is a solid power supply which has an interesting, unique feature—USB interfaces.
The voltages provided by this model are stable and constantly within specifications. In addition, the unit has a commendable level of efficiency in normal operation. It only drops very low in standby mode due to the integration of the USB interfaces.
The best buy recommendation is the older HX520W unit from Corsair. For right around $120, you get a solid power supply with modular, flat, flexible cables that are easy to install.
Despite the older design, the efficiency of the power supply can still impress even today, particularly under partial load and during standby.
The Fortron and the Everest 600 power supplies came up with a good idea, enabling partially passive operation. But our high expectations for the feature were not met. Their fans start up at a lower load than is specified and becomes very loud in the transition range.





















































