If you want to build an entirely silent PC, you have to (logically) either take out or replace everything that generates noise. Every moving part inside a PC generates noise, mainly fans and hard disk drives. A common source of noise that comes from a PC is the power supply unit. These high power devices require cooling and so there are fans installed inside them. A cheap, less efficient or extremely powerful unit is commonly cooled by a fast, noisy fan. As of late, companies try to make their units more ‘user friendly’, making them more efficient so as to require less cooling, and therefore to be as quiet as possible. Nevertheless, for something to be entirely quiet, it has to be missing any moving parts. And so some companies introduced extremely efficient, fanless power supply units which generate no noise at all, for the most demanding of users.

Today we will take a look at the Pacific 400W Fanless power supply unit from NorthQ. NorthQ is a company based in Denmark and we have had the opportunity to examine several of their products in the past. The Pacific 400W is probably the weakest, but by far the most efficient of their power supply unit product line. It is not very powerful and not on the cheap side either, but its special nature makes it ideal for specific applications and demanding users. Let us have a closer look at it.

Manufacturer features and specifications

Max output	+5V	+3.3V	+12V1	+12V2	-12V	+5VSB
Current	28A	20A	18A	18A	0.3A	3A
Max Wattage	180W		216W	216W	3.6W	15W
	400W

Key info:

- 0dB noise under normal conditions
- 12v ATX2.2 standard
- 80 % efficiency
- Green Power certified
- Grid case design for free airflow
- Build-in 70mm smart backup FAN
- ROHS certified
- PCIe
- 4 x S-ATA

Lifetime : 50,000 hours at 25°
Dimension:150*140*86mm   

70mm Backup Fan
This fan only turns on when the temperature reaches the limit temperature for fanless operation at 60C and will spin until the temperature is below threshold again and turn off.

Activate Temperature: 60C
FAN Size: 70 * 70 * 10mm
Rated Voltage: 12 V
Bearing Type: Sleeve bearing
Speed: 3000RPM
Airflow: 31,5CFM
Noise: 25dB(A)

Packaging and bundle

The cardboard box is thick and very sturdy, providing ample protection to the included unit. The design of the box is simple and names most of the key features.

The unit

The design of the Pacific is certainly unique. Every side of the black steel chassis is perforated, allowing for free airflow around the unit. That ought to aid the cooling, but it also should release a small amount of heat inside the computer case as well. At the rear of the unit, you can find a simple on-off switch and a status LED. The LED is meant to inform you if the unit is turned on or off, just in case your PC is so silent that you cannot understand it by any other way. There is nothing else placed on the chassis, not even large stickers or logos, in order to get the maximum possible airflow the perforated chassis can allow.

The Pacific is not a modular power supply unit, but the cables are well organized and not what we would class as overkill. All of the cables are sleeved and the connectors are black, which makes the unit look much tidier than a usual cheap unit. Beside the typical ATX and 4-pin 12V power connectors you can find four SATA power cables, four Molex cables, one floppy power cable and one PCIe 12V power connector. These are more than enough connectors for the capabilities of the Pacific.

Testing

To test the power supply unit, we will not connect it to an everyday system as we would be unable to know the exact load that we would provide and wouldn’t be able to vary the load. Instead we will use power resistors which are nothing more than normal resistors but capable of consuming a good amount of power. How much power depends on the resistance and capability of the resistor, and can be easily calculated by Ohm’s law (Amperes = Voltage / Resistance, Power = Voltage * Amperage).
Hence for example a 1Ohm resistor attached to the 3.3V line will allow 3.3A through it and consume about 10W of power. When adding two of these resistors in parallel, you double the power consumption and allow 20W to be consumed as you halve the resistance this way. Adding more will increase the power consumption. Of course that is not entirely accurate on paper as the fault tolerance of these resistors is high and almost none are exact to their resistance specifications, but after using them we could calculate how much power each bunch of them would consume accurately. This way we can add fake load to any power supply unit, and on any power line we wish with good accuracy.
For testing the NorthQ Pacific 400W unit, taking into account its design and power specifications, we took the following steps:

Total Load	3.3V Load	5V Load	12V-1 Load	12V-2 Load
33% (~140W)	6A (20W)	10A (50W)	5A (60W)	1A (12W)
50% (~200W)	10A (33W)	15A (75W)	5A (60W)	3A (36W)
75% (~300W)	10A (33W)	15A (75W)	8A (96W)	8A (96W)
100% (~400W)	15A (50W)	20A (100W)	10A (120W)	10A (120W)
110% (~440W)	15A (50W)	24A (120W)	12A (144W)	10A (120W)

	33% Load	50% Load	75% Load	100% Load	110% Load
3.3V	3.36V	3.34V	3.34V	3.34V	3.29V
5V	5.11V	5.10V	5.11V	5.05V	4.92V
12V-1	12.36V	12.34V	12.33V	12.34V	12.11V
12V-2	12.31V	12.33V	12.31V	12.28V	12.09V

The room temperature when the test took place was 20 Celsius degrees. The efficiency of the Pacific seems to be at the very least impressive. The back-up fan first started when we were stressing the unit at 75% load, but even then it would remain inactive most of the time. At 100% load, it would occasionally start, cool the unit and then stop again for a few minutes. It was also very impressive to see that the unit could work up to 440W load, 10% ABOVE its specified maximum capacity, without any problems and without the overload protection kicking in. A higher power load would make the unit shut down only seconds after powering it on, as the overload protection of the unit kicked in to protect the unit from permanent damage. However take note that the perforated design and efficiency of the Pacific gives it a vast advantage when working outside a computer case. Installing the Pacific in a warmer, tight for airflow space like the inside of a case will most probably reduce its efficiency slightly.

Final words and conclusion

What we did like:
The Pacific is designed to be as silent as a power supply can possibly get; the lack of any moving parts guarantee that the unit will generate no noise at all. While there are more fanless units in the market, most of them have large heatsinks expanding outside the chassis, towards the rear or the inside of the case, often causing compatibility problems. That is not true for the Pacific, which is not a millimetre larger than the ATX standard. The efficiency of the Pacific appears to be excellent as not much power is wasted and turned to heat, which is why the unit requires a minimal amount of cooling. 

What we did not like:

The Pacific is not very powerful and so it is not meant to power high end computer systems. But that is not a real problem for the Pacific, as gamers and enthusiasts with powerful systems rarely seek pure silence since most components that they install in their systems will generate a relative amount of noise anyway. The only real enemy of the Pacific is its pricing. Sure it is extremely efficient, maintaining an 80% efficiency minimum at all times, as well as being entirely silent. But the price tag of the Pacific has it on par with several 700W+ rated normal power supply units, which give the Pacific tough competition when taking into account the price to performance ratio.

Who we would recommend them to:
The Pacific is a power supply unit designed for specific uses and applications. It is extremely efficient and dead silent. It is only natural that silence freaks, especially HTPC users, will adore it. Its extreme efficiency makes it ideal for PC’s that stay on 24/7, such as file servers and internet PC’s, as it will save a noteworthy amount of power day after day.
Because of the exceptional efficiency and good performance of the Pacific, we believe that it is worthy of the DriverHeaven’s Editors Choice award.

The NorthQ Pacific 400W Fanless unit retails for about 100€ in the EU at the time of this review.


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