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 NEX750G 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 SuperNOVA NEX750G power supply is very good and meets the criteria for 80Plus Gold certification, even while operating on 115 VAC and at elevated temperatures.
80 Plus Program
Note 1: Power Factor ≥0.90 (50% to 100% Load)
Note 2: Tests conducted at room temperature (25°C)
Differential Temperature and Noise Levels
To simulate real world operation, 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, just like it would in a real PC.
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 ~28 dBA.
Starting out at low power and with a relatively cool ambient air temperature the fan noise was noticeable and just got worse as the load increased. At 50% load the fan noise was very noticeable. At 100% power the fan noise was subjectively loud. This probably won't be the power supply of choice for someone who is sensitive to fan noise.
Note: I was not able to take SPL measurements at the higher loads due to the background noise created by all the programmable DC load cooling fans running. At the lower test loads I am usually able to catch a moment when all the load fans have cycled off to take a SPL reading of just the PSU fan.
Shame that the regulation
Shame that the regulation isn’t a bit better. I love the modular design, but at the price there are some really nice Corsair models that are hard to compete with.
Indeed, why did they go with
Indeed, why did they go with group regulated Aurum, when there are way better designs on the market. I guess they thought having Gold certificate immediately makes unit premium class. Hint: it doesn’t.
Corsair makes the shittiest
Corsair makes the shittiest products since the comming of the so called “i” generation.
I’ve had 3 broken h100i’s so far.. A customer returning an AX760i and a AX1200i.. they all had the same issues, link broke after a while, causing shortage or something like that matter. And making the unit completely useless..
So b**** please, don’t tell people to go to corsair nowadays, it’s a shame how you people deny quality over a “name”.
I have this unit since the beginning and it never bricked on me.. the multi rails seem to be working super and I have none to minor fluctuation what so ever in my voltages and amps.
And I hear people say stuff, like yeah MULTI RAIL IS BAD.. Damn people this aren’t the 2004’s anymore.. This unit was build like a GOOD multi rail.. not a dual rail 10a + 25a hybrided together like OCZ used to do.
This PSU is a joke, end of
This PSU is a joke, end of story.
I got the 650 supernova for
I got the 650 supernova for $70. From the small number of reviews I have read I think it is a bargain. $100 seems to be about the price now. I also got free shipping.:-) I have a Thermaltake toughpower 675 which has been great. The evga is going to replace a old thermaltake 430 with only 20 pin atx connector and 4 pin cpu..
It is amazing to me all the
It is amazing to me all the power supply aficionados. Well they think they are anyway. They are in fact followers not leaders and parrot what they hear from their masters….really, it gets old. Spend their life in their moms basement and spend someone elses money to get their rigs built.
This is a quality unit, it is not the best out there but it is light years from the worst. If you get it at a good price it will serve you well. The 650G runs an overclocked AMD FX based system complete with all the accessories, water cooling system etc…….also drive two 770s heavily overclocked with the voltage to board mod to run the voltages I want and the clocks as high as I can. That wasnt the original plan, it was planned for a single 770, but thats what it is and it runs it fine because it doesnt just say “650” on the side of it, it runs at just below that number continuously. Hold it in your hand and you will see and feel the quality. Then there is the 10 year warranty, you can see how scared that EVGA is the build quality of this PSU sucks. I get tired of the disinfo. To the above negative poster, put down your coolermaster or sparkle magic PSU and step up to a decent PSU. Thank me later.
cheers for the sensible
cheers for the sensible comments, I was struggling to decide on a psu as I keep running into dumbass commentors, I narrowed it down to this precisely because they were bold enough to stick a 10 year warranty on it… 10 years for christs sake,, 10 yrs is a great statement on their belief in this psu.. what could you possibly whinge about with that….
and before it even gets said,
and before it even gets said, when you register this unit with evga, it adds 5 more years on the warranty.
$89 with rebate at
$89 with rebate at MicroCenter. That makes this a very good PSU for the price.
Is it really that bad+ i am
Is it really that bad+ i am 14 and i have a i5 4670K, Asus maximus Hero and a 780 Classy. Is this psu so bad? 🙁
Is it really that bad+ i am
Is it really that bad+ i am 14 and i have a i5 4670K, Asus maximus Hero and a 780 Classy. Is this psu so bad? 🙁