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) 750 watts of AC power going in would result in 750 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 Supernova 750W G3 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 EVGA 750W Supernova G3 power supply is very good and meets the criteria for 80 Plus Gold certification, even while operating on 120VAC and at elevated temperatures.
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.
Note: The EVGA 750 G3 power supply was tested with the ECO Thermal Control System switched On (enabling fan-less operation).
* Fan not spinning
With the ECO Intelligent Thermal Control System engaged the PSU was silent throughout the first two tests. Once the cooling fan started to spin under a 50% load, the noise was still very quiet. Finally, at full load, with an elevated ambient temperature, the 750W G3 PSU cooling fan noise became very noticeable.
(Courtesy of EVGA)
Who is the actual
Who is the actual manufacturer? Do EVGA produce it themselves or they are partnering with Seasonic or CWT etc ?
“Here are a few pictures
“Here are a few pictures showing the layout and components inside the EVGA Supernova 750W G3 power supply. The Supernova G3 Series is built by Super-Flower and is based on a second generation Leadex platform.”
Have the powersupply
Have the powersupply manufacturers ever standardized the modular connectors? I have a bunch laying around that I am too chicken to try.
Hi, I asked in the office
Hi, I asked in the office chat and unfortunately the answer is no. The modular connectors are not standardized between manufacturers or even between PSUs from the same manufactures (sometimes you can swap them within the same line but not always).
Good review!
Question: how
Good review!
Question: how well does this compare to the Seasonic Focus Plus series (SSR-750FX) in your opinion? The F+ kindasorta won by a slim margin in JohnnyGuru’s testing, but their rating system is a little… eccentric.
Obviously they’re both awesome units but if you had to choose…
I’ve been a SS loyalist and pricing on the F+ series is very competitive, but there was some concern with the F+ units’ small fan resulting in annoying noise.
Another question: what’s the benefit of a fully modular PSU? Do they expect people to run their PSUs without the ATX12v cable? Is it just for easy-ish replacement if you happen to damage a cable? Would be a lot more valuable IMHO if they bundled shorter and longer cables for different case/mobo combos.
Thanks, its always good to
Thanks, its always good to know that readers find our reviews helpful.
First question: Yes, both the EVGA 750W G3 and the Seasonic 650W Focus+ Gold PSUs proved to be excellent. Performance wise they are very close, both with very good voltage regulation, AC ripple suppression and efficiency (the 750W G3 had slightly better AC ripple suppression). The EVGA G3 also uses a slightly larger fan (128mm vs the Seasonic F+ 120mm) but they both are relatively quiet through mid-power range and both have FDB. And they are both backed by a 10-year warranty. So your final purchasing decision may come down to price – which one has the lower cost when you want to buy one (at this moment the Seasonic 750W F+ is about $20 less than the EVGA 750W G3).
Second question: I personally prefer a semi-modular PSU with a fixed 24-pin, 4+4 ATX CPU, and a pair of PCI-E cable/connectors. Its not like these are optional. Being fully modular adds more connection points (potential for added resistance/slight voltage drop) and a little bulk to the front of the PSU. I suspect manufacturers are going fully modular to lower production costs by eliminating the extra labor required to hand solder fixed leads.