Efficiency, Differential Temperature and Noise
Efficiency
Efficiency is defined by the power output divided by the power input and is usually expressed as a percentage. If a PSU were a 100% efficient (which none are) 850 watts of AC power going in would result in 850 watts of DC power coming out (with no waste heat to dissipate). In the real world there are always inefficiencies and power is lost in the form of heat during the conversion process. Newer revisions to the ATX12V Power Supply Design Guide V 2.2 have continued to increase the efficiency recommendations for PC switching mode power supplies and now lists both required and recommended minimum efficiencies.
We measured the AC power input to the 850W Enigma PSU with an Extech power analyzer while the total DC load was found by adding all the individual +3.3V, +5V, +12V, -12V and +5VSB loads together.
The overall efficiency of the Riotoro Enigma 850W power supply is very good and meets the criteria for 80 Plus Gold certification, even while operating on 120VAC and at elevated temperatures. The efficiency quickly ramps up and stays high through the 50% load mark where it then starts dropping back down.
80 Plus Program
Note: Tests conducted at room temperature (25°C)
Differential Temperature and Noise Levels
To simulate a demanding environment, some of the warm exhaust air from the PSU under test is recirculated back to the intake through a passive air duct, which allows the PSU air inlet temperature to increase with load, up to 40°C.
The differential temperature across the power supply was calculated by subtracting the internal case air temperature (T in) from the temperature of the warm exhaust air flowing out the back of the power supply (T out).
Thermocouples were placed at the air inlet and exhaust outlet. The ambient room air temperature was 23ºC (74ºF) +/- 0.5ºC during testing.
T out = temperature of air exhausting from power supply
T in = temperature of air entering power supply
Delta T = T out – T in
Sound pressure level readings were taken 3’ away from the rear of the case in an otherwise quiet room. The ambient noise level was ~27 dBA.
The Enigma 850W PSU started out relatively quiet and stayed that way up to the 50% load mark. Above 50% load the cooling fan gradually increased in speed and the noise became very noticeable. I was not able to take a SPL reading at the 100% load mark due to all the programmable DC load cooling fans staying on.
(Courtesy of Riotoro)
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.