NorthQ Silent Lightning 400W PSU

NorthQ Silent Lightning 400W PSU, 30% Load

Voltage line	Power load	Voltage line	Power load
3,3V	6A	12V1	5A
5V	5A	12V2	3A

3,3V	5V

12V1	12V2

NorthQ Silent Lightning 400W PSU, 50% Load

Voltage line	Power load	Voltage line	Power load
3,3V	6A	12V1	6A
5V	10A	12V2	5A

3,3V	5V

12V1	12V2

NorthQ Silent Lightning 400W PSU, 75% Load

Voltage line	Power load	Voltage line	Power load
3,3V	12A	12V1	9A
5V	10A	12V2	9A

3,3V	5V

12V1	12V2

NorthQ Silent Lightning 400W PSU, 100% Load

Voltage line	Power load	Voltage line	Power load
3,3V	12A	12V1	14A
5V	10A	12V2	12A

3,3V	5V

12V1	12V2

NorthQ Silent Lightning 400W PSU, efficiency graph

Power load	30%	40%	50%	60%	70%	80%	90%	100%
Efficiency	77%	78%	78%	78%	76%	76%	75%	72%

Although the Silent Lightning was overall a stable unit and worked fine across its entire output range, it was unfortunately not a magnificent performer either. The efficiency of the unit is (average at best) 75%, which is nothing special but not irregular for a 400W unit at the same time. Unfortunately this was also the first unit we ever tested which we could not complete a variable load voltage regulation test. When switching from very low loads to very high loads instantly (40W to 400W for instance) the unit would shut down. This is probably due to an over-sensitive over current protection circuit and poses no real threat to regular users as such load changes are not going to happen inside a typical PC, but left us bewildered nonetheless.

The Silent Lightning will not be winning any awards for its efficiency, but that doesn’t mean that the unit is noisy either. The massive 140mm fan is providing more than enough airflow for the unit to stay cool and silent across most of its power range. It only speeds up when the unit is loaded over 75% and still it remains pretty quiet. The low power output of the unit despite the average efficiency will not allow much power to be wasted as heat, so it should pose no challenge to the cooling system of the unit.