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Load Regulation, Hold-Up Time, And Inrush Current

To learn more about our PSU tests and methodology, please check out How We Test Power Supply Units.

Corsair SF750

Corsair SF600 Platinum

Corsair SF600

Primary Rails And 5VSB Load Regulation

Load Regulation testing is detailed here.

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Hold-Up Time

Our hold-up time tests are described in detail here.

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Despite a small bulk cap, the EPF500AWT's hold-up time easily exceeds 17ms, satisfying the ATX spec. The power-good signal also lasts more than 16ms, and it's accurate, dropping before the rails go out of spec.

Inrush Current

For details on our inrush current testing, please click here.

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Measured inrush current is quite high, given the PSU's moderate capacity.

Load Regulation And Efficiency Measurements

The first set of tests reveals the stability of the voltage rails and the EPF500AWT's efficiency. The applied load equals (approximately) 10 to 110 percent of the PSU's maximum load in increments of 10 percentage points.

We conducted two additional tests. During the first, we stressed the two minor rails (5V and 3.3V) with a high load, while the load at +12V was only 0.1A. This test reveals whether a PSU is Haswell-ready or not. In the second test, we determined the maximum load the +12V rail could handle with minimal load on the minor rails.

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Test #	12V	5V	3.3V	5VSB	DC/AC (Watts)	Efficiency	Fan Speed	Fan Noise	Temps (In/Out)	PF/AC Volts
1	2.323A	1.973A	1.963A	0.976A	49.776	86.006%	580 RPM	20.8 dB(A)	37.07°C	0.930
12.140V	5.066V	3.358V	5.109V	57.875	41.44°C	115.05V
2	5.679A	2.958A	2.952A	1.177A	99.758	90.413%	580 RPM	20.8 dB(A)	38.46°C	0.963
12.135V	5.059V	3.348V	5.094V	110.336	43.09°C	115.04V
3	9.384A	3.465A	3.470A	1.376A	149.914	91.522%	580 RPM	20.8 dB(A)	39.29°C	0.972
12.130V	5.052V	3.340V	5.080V	163.801	44.16°C	115.04V
4	13.081A	3.963A	3.959A	1.576A	199.768	91.853%	600 RPM	21.4 dB(A)	39.20°C	0.973
12.124V	5.045V	3.333V	5.066V	217.487	44.62°C	115.04V
5	16.445A	4.970A	4.964A	1.781A	249.787	91.768%	720 RPM	24.5 dB(A)	39.58°C	0.976
12.118V	5.034V	3.322V	5.051V	272.194	45.44°C	115.06V
6	19.806A	5.971A	5.975A	1.985A	299.700	91.446%	920 RPM	31.7 dB(A)	40.27°C	0.981
12.113V	5.024V	3.313V	5.036V	327.734	46.44°C	115.05V
7	23.178A	6.981A	6.990A	2.191A	349.729	91.042%	930 RPM	32.1 dB(A)	41.48°C	0.985
12.107V	5.017V	3.303V	5.021V	384.142	48.22°C	115.07V
8	26.542A	7.991A	8.013A	2.396A	399.654	89.748%	940 RPM	32.3 dB(A)	41.99°C	0.990
12.104V	5.007V	3.293V	5.005V	445.307	50.47°C	115.07V
9	30.346A	8.502A	8.558A	2.402A	449.682	89.381%	940 RPM	32.3 dB(A)	42.92°C	0.992
12.097V	4.999V	3.282V	4.995V	503.106	53.08°C	115.08V
10	34.101A	9.028A	9.064A	2.504A	499.564	88.876%	940 RPM	32.3 dB(A)	43.77°C	0.994
12.092V	4.989V	3.276V	4.984V	562.091	54.59°C	115.08V
11	38.249A	9.038A	9.080A	2.512A	549.573	88.290%	940 RPM	32.3 dB(A)	44.78°C	0.995
12.088V	4.983V	3.269V	4.976V	622.462	59.10°C	115.08V
CL1	0.099A	12.011A	12.003A	0.005A	101.674	86.913%	940 RPM	32.3 dB(A)	43.57°C	0.966
12.139V	5.038V	3.327V	5.107V	116.984	50.52°C	115.08V
CL2	40.958A	1.003A	1.001A	1.003A	508.577	89.619%	940 RPM	32.3 dB(A)	44.27°C	0.994
12.090V	5.012V	3.301V	5.048V	567.489	57.19°C	115.08V

Load regulation at +12V is tight, and it's merely satisfactory on the other rails. The fan's noise remains at low levels, even when we push the PSU to its limits (and above them). Enermax's fan does a fine job, given the large temperature deltas that our equipment recorded.

As for efficiency, the EPF500AWT clears our 20% load test easily. It also comes close to the 80 PLUS Platinum certification's requirements in the 50% and 100% load tests. After all, 80 PLUS tests at a very low ambient, so it's natural to see worse results when we test at more realistic temperatures.

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Aris Mpitziopoulos is a Contributing Editor at Tom's Hardware US, covering PSUs.

10 Comments Comment from the forums

skoalreaver

Sleeved cables are not justification for poor build quality and that crazy price.
Reply
eglass

I'd probably buy it. I like those cables and I'm running a 500W Enermax Liberty that is now 11 years old.
Reply
Anathemata

How well does the dust-removal feature work? I mean, Van der Waals force is still a thing, and you need more than just a simple fan to blow out dust. Wouldn't a simple filter suffice?

The sleeved cables are a nice touch. It'll be cheaper than buying a different power supply and separate sleeved cables.
Reply
daddywalter

Build quality isn't bad but could be better; lack of OTP is troublesome; and I'll agree with the reviewer that sleeved cables would be better offered as an option for modders. 80 Plus Platinum rating is a plus, of course; and 500 watts is adequate for most general-purpose computers that don't require multiple GPUs -- this PSU would probably outlast most SOHO builds, but then the initial price becomes more of a factor. Nice PSU, but IMHO not worth $140 with only a five-year warranty; at ten years I might consider it since then it should be good for at least three builds.
Reply
dstarr3

19274544 said:
I'd probably buy it. I like those cables and I'm running a 500W Enermax Liberty that is now 11 years old.

11 years is plenty of time for a company to have since dropped an amount of build quality.
Reply
Robert Cook

I'll add my voice, that auto play video needs to go. It is obnoxious, and adds lag to weaker devices.

I like that cable pattern, it reminds me of the cables on my Enermax revolution 85+ 850W. (a great PSU despite its lower efficiency and age.)

How are poorly trimmed leads going to cause shorts if everything is locked inside a case? I only see that as an issue if you go dropping screws in there.
Reply
Aris_Mp

they aren't poorly trimmed only, some of them are really long and only a hair away from the other. Under extreme conditions this can cause problems (shorts) and there can be of course an EMI issue when leads are so close to each other. Also with such long leads the plastic shield under the PCB can get punctured or during the PCB's installation into the chassis, which applies pressure to the leads, the long ones will bend and probably get shorted; this means that some PSUs might be already broken. I don't think that every PSU that leaves the production line is tested, but only a percentage of them.

There is a purpose behind the proper trimming of excessively long leads in every PCB that is installed into a metallic chassis. The use of a plastic shield under the PCB doesn't automatically solves all possible problems.
Reply
WFang

I'm hoping for a resurgence in power supply choices in the 500W and *LESS* category!

I would rather see something like the amazing Seasonic Prime supplies in a 400W flavor than 600W and over...

Before I go on, I realize that if you run two GPU's or you really like to OC, obviously you need more and want more.. Great.. you already have a ton of great choices for those use-cases... I just wonder why we don't have more great quality choices in the lower Wattage ranges where probably a good 75% of even the enthusiast group could live comfortably.

I also realize that TDP - Thermal Design Power is NOT the same as power consumption, but it is easy to find TDP numbers, and a part that is designed to deal with e.g. 100W TDP is likely to consume around 100W (or less) even in peak. As such it becomes a handy metric for back of the envelope power budgeting that still ends up being fairly conservative.

With CPU's now more often in the lower half of 45W, 65W, and 95W TDP and the more recent GPU's all sitting at 300W or less in TDP, I'd argue that for non-OC'ed systems with one GPU and 1 or 2 HDD's and maybe an SSD, a great high efficiency 350W to 400W PSU will be a great choice. Feeling like that is pushing it? Fine, go 500W... but I don't see why you'd shop higher than that (for this use-case). Yet, good quality Titanium, Platinum, or Gold efficiency PSU's seem so hard to find in the sub 500W range. :(

On a side note, since I'm here complaining anyway: A looong time ago I heard Tom's mention the Seasonic Prime 600W fanless PSU, anyone know if/when that will become available in the US? (Or anywhere?)???
Reply
Aris_Mp

I am informed that the Prime 600W fanless will be available somewhere in 2017.
Reply
Marcus52

19274544 said:
I'd probably buy it. I like those cables and I'm running a 500W Enermax Liberty that is now 11 years old.

Enermax was my favorite PSU maker when they made their own, but unfortunately they've chosen OEMs that are "adequate" not "great" to replace their manufacturing facility. I've paid their premium in the past, but right now EVGA is on the top of my list. Super Flower makes their top-of-the-line PSUs and build quality is superb, as are test bench results.

Seasonic is also on my list of "will buy", and several other brands use Seasonic or Super Flower, so I wouldn't be opposed to buying one from someone like Corsair - as long as it tested well on reputable hardware sites.

Never buy a PSU that doesn't review well. I've learned that the hard way. Build quality matters.

Reply

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Enermax D.F. 500W PSU Review

The Enermax D.F. 500W is a fully modular PSU featuring high efficiency, quiet operation, and individually sleeved cables. But are those enough to justify its premium price tag?

Load Regulation, Hold-Up Time, And Inrush Current

Primary Rails And 5VSB Load Regulation

Hold-Up Time

Inrush Current

Load Regulation And Efficiency Measurements