Test Setup
All measurements are performed utilizing a custom designed and built load tester, called Faganas, which is able to stress PSUs up to 1800 Watts. We also use a DS1M12 (Stingray) oscilloscope, a CHY 502 thermometer, a Fluke 175 multimeter and an Instek GPM-8212 power meter. Furthermore, in our setup we have included a wooden box, which along with a heating element is used as a Hot Box. Finally, we have at our disposal nine electronic loads (six Array 3711A, 300W each, and three Array 3710A, 150W each), a Rigol 1052E oscilloscope and a CEM DT-8852 sound level meter. In the near future the electronic loads will form our new test set up, which with the help of our custom built software will have the same capabilities with the, ultra expensive, Chroma ATEs. In
this article you will find more details about our equipment and the review methodology we follow.
Voltage Regulation Charts
The following charts show the voltage values of the main rails, recorded over a range from 60W to the maximum specified load, and the deviation (in percent), when compared with the voltage values at 60W load.
Efficiency Chart
In this chart you will find the efficiency of SPCR2-850P at low loads and at loads equal to 20-100% of PSU’s maximum rated load.
Voltage Regulation and Efficiency Measurements
The first set of tests reveals the stability of voltage rails and the efficiency of SPCR2-850P. The applied load equals to (approximately) 20%, 40%, 50%, 60%, 80% and 100%, of the maximum load that the PSU can handle. In addition, we conduct two more tests. In the first we stress the two minor rails (5V & 3.3V) with the maximum load that our tester can apply to these rails, while the load at +12V is only 2A and in the second test we dial the maximum load that +12V can handle while load at minor rails is minimum.
Voltage Regulation & Efficiency Testing Data Scythe SPCR2-850P |
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Test | 12 V | 5 V | 3.3 V | Power (DC/AC) | Efficiency | Temp (In/Out) | PF/AC Volts |
20% Load | 13.135A | 2.034A | 2.191A | 178.25W | 88.53% | 42.3°C | 0.817 |
12.222V | 5.109V | 3.341V | 201.35W | 44.1°C | 228.0V |
40% Load | 24.571A | 4.906A | 5.970A | 342.98W | 89.61% | 43.5°C | 0.882 |
12.151V | 5.063V | 3.280V | 382.75W | 46.3°C | 231.2V |
50% Load | 30.486A | 6.902A | 8.075A | 430.07W | 89.72% | 45.8°C | 0.902 |
12.110V | 5.025V | 3.245V | 479.35W | 49.3°C | 228.9V |
60% Load | 37.232A | 6.896A | 8.061A | 510.36W | 89.74% | 47.7°C | 0.914 |
12.078V | 5.018V | 3.234V | 568.70W | 51.5°C | 228.2V |
80% Load | 50.360A | 8.934A | 9.599A | 679.51W | 88.77% | 49.6°C | 0.935 |
12.004V | 4.968V | 3.188V | 765.50W | 54.4°C | 229.0V |
100% Load | 65.603A | 8.911A | 9.582A | 857.27W | 87.48% | 51.2°C | 0.950 |
11.933V | 4.945V | 3.169V | 980.00W | 57.8°C | 228.7V |
Crossload 1 | 1.972A | 19.999A | 16.927A | 175.86W | 80.71% | 50.1°C | 0.822 |
12.156V | 4.914V | 3.167V | 217.90W | 53.5°C | 230.2V |
Crossload 2 | 70.826A | 1.953A | 2.108A | 863.26W | 88.22% | 51.4°C | 0.950 |
11.953V | 5.025V | 3.255V | 978.50W | 58.3°C | 228.3V |
Efficiency is high, even at the excessive temperatures at which we conduct our tests. Also the PSU had no problem at all to deliver its full power at 51°C operating temperature. As for voltage regulation at +12V, it is below 3%, at 5V it's 3.49% and at 3.3V it goes over the 5% limit, reaching 5.63%. In general voltage regulation on all rails is on the loose side. Finally PF readings were really low and only with 50% load PF surpasses 0.9. The 80 Plus Silver certification requires PF to be over or equal to 0.9 beyond 20% load of max rated capacity, however they test at only 23°C while we test at double that and as it seems the APFC on this unit is prone to high ambient temperatures.
Efficiency at Low Loads
In the next tests, we measure the efficiency of SPCR2-850P at loads much lower than 20% of its maximum rated load (the lowest load that the 80 Plus Standard measures). The loads that we dial are (approximately) 40, 65 and 90W. This is important for scenarios in which a typical office PC is in idle with power saving turned on.
Efficiency at Low Loads Scythe SPCR2-850P |
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Test # | 12 V | 5 V | 3.3 V | Power (DC/AC) | Efficiency | PF/AC Volts |
1 | 1.965A | 2.050A | 2.208A | 42.02W | 74.04% | 0.553 |
12.259V | 5.126V | 3.361V | 56.75W | 232.5V |
2 | 3.956A | 2.048A | 2.204A | 66.36W | 79.86% | 0.631 |
12.252V | 5.124V | 3.358V | 83.10W | 232.4V |
3 | 6.024A | 2.046A | 2.197A | 91.57W | 83.44% | 0.670 |
12.239V | 5.121V | 3.352V | 109.75W | 232.7V |
Efficiency at low loads is satisfactory, for the capacity and the efficiency certification of the unit. With 66W load the 80% mark is almost reached and with 91.5W efficiency hits 83.5%.
Power Consumption in Idle & Standby
In the table below you will find the power consumption and the voltage values of all rails (except -12V), when the PSU is in idle mode (On but without any load at its rails) and the power consumption when the PSU is in standby (without any load at 5VSB).
Idle / Standby Scythe SPCR2-850P |
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Mode | 12 V | 5 V | 3.3 V | 5VSB | Power (AC) | PF/AC Volts |
Idle | 12.292V | 5.151V | 3.385V | 5.166V | 6.39W | 0.197 |
229.9V |
Standby | 0.34W | 0.013 |
230.4V |
Phantom power is very low, at 0.34W, so the unit is ErP Lot 6 ready not only for the current, but also for the future (2013) requirements.