DC Load Regulation and AC Ripple
Testing Methodology
Establishing an accurate load is critical to testing and evaluating a PC power supply. PCPerspective’s power supply test bench can place a precise DC load on the PSU under test. Each power supply is tested under controlled, demanding conditions up to its maximum rated load (at 40ºC). Our current suite of tests includes:
• DC Load Regulation
• AC Ripple and Noise
• Efficiency
• Differential Temperature
• Noise
The Riotoro Enigma 850W power supply was evaluated on both features and performance. A full range of equipment was used to test the power supply under controlled load conditions.
• (2) CSI3710A Programmable DC load (+3.3V and +5V outputs)
• (4) CSI3711A Programmable DC load (+12V1, +12V2, +12V3, and +12V4)
• (2) 200W Precision resistor load bank (+12V5 and +12V6)
• Switchable precision resistor load bank (-12V and +5VSB)
• Agilent 34401A digital multimeter (Accuracy ±0.0035% vDC)
• Extech 380803 Power Analyzer (Accuracy ±0.5% of full scale)
• DS1M12 "StingRay" digital oscilloscope (20M S/s with 12 Bit ADC)
• Extech Model 407738 digital sound level meter (Accuracy ±1.5 dB)
The following connectors were used to attach the Enigma 850W PSU to the PCPerspective power supply test equipment.
• (1) 20+4 pin ATX
• (1) 8-pin EPS/ATX12V
• (4) 6-pin PCI-E
• (6) SATA
• (6) Molex
DC Output Load Regulation
To simulate demanding and maximum loading conditions, the Riotoro 850W Enigma power supply was connected to the load testers and supplied with 120 VAC. In this test we are interested in seeing how well a PSU can maintain the various output voltages while operating under different loads.
The ATX12V V2.2 tolerance for voltages states how much each output (rail) is allowed to fluctuate and has tighter tolerances now for the +12V outputs. I have also included a second table of expanded tolerances (±1% to ±6%) for reference.
The following tables list the DC voltage results for the 850W Enigma PSU while operating on 120 VAC, 60 Hz.
The 850W Riotoro Enigma PSU produced very good voltage regulation, particularly on the three main outputs, which stayed within ±2% of the recommended guidelines.
AC Ripple and Noise on the DC Outputs
The amount of AC ripple and noise present on the DC outputs was checked using a digital oscilloscope. This AC component may be present in the KHz range where most switching power supplies operate or it may be more prevalent at the 60 Hz line frequency. We adjust the O-scope time base to look for AC ripple at both low and high frequencies. The ATX12V V2.2 specification for DC output noise/ripple is defined in the ATX12V Power Supply Design Guide.
Ideally we would like to see no AC ripple (repetitive) or noise (random) on the DC outputs – the cleaner the better! But in reality there will always be some present. I measured the amplitude of the AC signal (in millivolts, peak-to-peak) to see how well the power supply complied with the ATX standard. The following table lists the ripple/noise results during all of the load tests for the main output voltages of interest.
The Riotoro Enigma 850W power supply was a bit of a mixed bag when it came to AC ripple and noise suppression. The +3.3V and +5V rails stayed well under control but the more important +12V output showed higher levels of AC ripple than we would like to see, but well within the range of the ATX guidelines.
Is there any PSU with fan(s)
Is there any PSU with fan(s) capable of evicting the heat equivalent of its nominal power?
Yes, most any enthusiast
Yes, most any enthusiast grade PSU uses a fan capable of exhausting the waste heat generated at 100% load. You might also want to consider how much noise is generated at that level and the quality of the fan. A cheap fan that fails early will most likely take the PSU with it.
Literal rip-off of the
Literal rip-off of the legendary AX 850 of Corsair’s (OEMed from SeaSonic), except this one’s worse because it’s not fully modular and probably has sub-par chokes.
As the reviewer pointed out,
As the reviewer pointed out, the Enigma 850W is made by the same OEM as The Corsair CS850M (not the AX850). And I would say that being semi modular is better than being fully modular. It’s not like those 24 pin ATX and 4 pin CPU cables are optional. Not having the extra connectors on the front of the power supply just eliminates potential problems (oxidation, extra voltage drop, etc.) and gives a little more flexibility to the cables for easier routing.
Really?
A “silver award” for
Really?
A “silver award” for a product that has competition at it’s price-point that is fully modular?
Then there is the “suspect quality” of some of the parts used in this device as noted by another more skillful reviewer on another web site.
Lee ought to retire before his “cream puff” reviews short him out.
Dude, who pissed in your
Dude, who pissed in your Wheaties? I have to agree with the Silver award. It seems this power supply has enough good things going for it to earn a little recognition, but not ready for Gold. And as the reader above pointed out being fully modular is not an advantage, it’s a disadvantage! I’ve been working in IT support for over 12 years so I know a little about PCs and power supplies.
The main reason manufacturers build fully modular power supplies is to save labor, which saves them money. It does not offer any advantage to the user. Modular connectors can be soldered on machines but fixed cables require hand soldering. A semi modular power supply offers the best combination of reliability and flexibility.
I for one appreciate the power supply reviews these guys provide and I hope they keep them coming for a long time.