One of the screws that open the case is covered under a warranty sticker. If the seal is broken, so is your warranty.
- The PSU is connected to an APC SmartUPS which supplies clean 220V input.
- AC current is measured using a Peaktech 4010 desktop RS232 multimeter with 0.02A accuracy.
- To measure DC output voltages of the PSU we use a Keithley 2700 6.5 digit data acquisition system. All three input voltages are measured at the same time using a solid state switching system.
- Power Factor is measured using a generic Power Efficiency Meter.
- Measurements for Ripple Voltage were obtained using a 100 MHz Tektronix TDS224 Digital Storage Oscilloscope.
Our efficiency testing setup consists of three high-power resistors and a Socket A motherboard. The motherboard creates a small load which makes sure the PSU turns on (some PSUs require a minimum load). Since there is no hardware installed in the motherboard, its power draw is negligible. The three resistors create a static load of about 350W - a typical high-performance system. The actual real power draw will be calculated during testing by measuring voltage and current. Please note that we are testing efficiency at only a single load value, other tests measure at different loads and/or over the whole load range. For a PSU to be 80+ Certified it needs to be 80% efficient at 20%, 50% and 100% load.
Fan noise measurements are performed using the efficiency testing rig and a Bruel & Kjaer 2236 sound level meter. The 2236 is a professional grade sound level meter (~$4,000), measurements are conducted at 100 cm distance and 160 cm over the floor. The ambient background noise level in the room is well below 20 dbA for all measurements. Please note that the dbA scale is not linear, it is logarithmic. 40 dbA is not twice as loud as 20 dbA. A 3 dbA increase results in double the sound pressure. The human hearing is a bit different and it is generally accepted that a 10 dbA increase doubles the perceived sound level.