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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.

Silverstone ST1500-GS

EVGA SuperNOVA 1600 G2

EVGA SuperNOVA 1600 P2

Primary Rails And 5VSB Load Regulation

Load Regulation testing is detailed here.

Image 1 of 8

Hold-Up Time

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

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The hold-up time easily surpassed the minimum allowed limit that the ATX spec sets. The advanced design of this platform allowed for this good result, since the combined capacity of the bulk caps is rather low for such a strong PSU. To give you an example, the Super Flower Leadex Titanium unit has much larger bulk caps with 1,560µF combined capacity; however, it registers a significantly lower hold-up time of 16 ms.

Inrush Current

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

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The inrush current is pretty low for a PSU, with 1.5kW max power.

Load Regulation And Efficiency Measurements

The first set of tests reveals the stability of the voltage rails and the PSU's efficiency. The applied load equals (approximately) 10 to 110 percent of the maximum load the supply can handle, 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 0.10A. 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.

Swipe to scroll horizontally

Test	12V	5V	3.3V	5VSB	Power (DC/AC)	Efficiency	Fan Speed	Fan Noise	Temp (In/Out)	PF/AC Volts
10%	10.705A	2.004A	1.999A	1.004A	149.78W	90.99%	0 RPM	0 dBA	45.54°C	0.986
11.975V	4.993V	3.300V	4.967V	164.61W	42.06°C	115.1V
20%	22.432A	3.000A	2.999A	1.209A	299.70W	92.81%	0 RPM	0 dBA	47.38°C	0.984
11.986V	4.986V	3.296V	4.956V	322.93W	43.52°C	115.1V
30%	34.511A	3.509A	3.517A	1.410A	449.74W	93.62%	0 RPM	0 dBA	48.74°C	0.991
11.987V	4.984V	3.296V	4.949V	480.39W	44.43°C	115.1V
40%	46.591A	4.014A	4.002A	1.614A	599.59W	93.37%	376 RPM	18.5 dBA	40.81°C	0.994
11.986V	4.980V	3.295V	4.942V	642.19W	50.50°C	115.1V
50%	58.304A	5.004A	4.997A	1.814A	749.45W	93.28%	536 RPM	22.9 dBA	41.94°C	0.996
11.989V	4.990V	3.302V	4.948V	803.45W	52.23°C	115.1V
60%	70.087A	6.014A	6.001A	2.020A	899.33W	92.61%	632 RPM	25.8 dBA	42.43°C	0.997
11.979V	4.986V	3.298V	4.940V	971.13W	53.94°C	115.1V
70%	81.848A	7.017A	6.999A	2.225A	1049.18W	91.77%	768 RPM	30.7 dBA	44.28°C	0.997
11.975V	4.985V	3.299V	4.935V	1143.24W	56.78°C	115.1V
80%	93.580A	8.014A	7.984A	2.429A	1199.18W	90.77%	952 RPM	34.5 dBA	45.65°C	0.998
11.977V	4.990V	3.305V	4.938V	1321.19W	59.54°C	115.1V
90%	105.787A	8.518A	8.500A	2.429A	1349.26W	89.85%	1392 RPM	45.6 dBA	47.00°C	0.998
11.974V	4.988V	3.305V	4.935V	1501.73W	61.34°C	115.2V
100%	117.509A	9.028A	8.982A	3.564A	1499.03W	89.02%	1704 RPM	51.4 dBA	48.62°C	0.998
11.972V	4.988V	3.307V	4.904V	1683.90W	63.22°C	115.2V
103%	121.648A	9.028A	8.980A	3.565A	1549.07W	89.04%	1800 RPM	52.9 dBA	48.81°C	0.998
11.976V	4.988V	3.307V	4.904V	1739.84W	63.86°C	115.1V
CL1	0.099A	22.028A	19.998A	0.000A	177.48W	84.06%	1544 RPM	49.0 dBA	45.62°C	0.978
11.982V	4.979V	3.331V	5.018V	211.13W	56.00°C	115.1V
CL2	124.935A	1.002A	1.003A	1.001A	1507.39W	89.19%	1728 RPM	51.6 dBA	47.61°C	0.998
11.959V	4.997V	3.298V	4.975V	1690.15W	61.97°C	115.1V

The results of these tests are really good, showing the advantages of digital control. Load regulation is almost perfect on the +12V, 5V and 3.3V rails, while at 5VSB it is very good as well, staying within 2 percent. On top of that, the PSU achieved really high efficiency levels; however, with 50 percent of its max-rated-capacity load and with full load, it didn't manage to hit the really high 80 Plus Titanium requirements (94 and 90 percent), at least during the tough conditions under which we conducted our tests. Finally, although we pushed the AX1500i very hard, it managed to operate quietly, and the noise went high only with very high loads (90 percent and above).

During our overload test, we had shutdowns with anything above 1600 W after a while, so we stayed at 1550W, where the PSU operated without any problems, even at 49°C ambient temperature. In the past, we tested two AX1500i units with both of them, easily delivering 1650W of power with the same tough conditions in place; however, this unit didn't do us that favor. Since it isn't wise to operate a PSU beyond its limits, we won't consider the strict overpower limit of the AX1500i as a negative.

Corsair Link Screenshots

You will find several screenshots of the Corsair Link software below, which we took during our test sessions.

Image 1 of 13

The efficiency levels and the watt power consumption that the Corsair Link application provides aren't very accurate, especially as the load increases. We could say that they are very optimistic — showing significantly higher efficiency levels — than the ones that we measured with our lab-grade equipment. We also noticed that at a level of amperes of around 4.5A and below, the Corsair Link app shows zero ampere readings on the PCIe and EPS connectors. Corsair should provide a fix for this issue as soon as possible.

Current page: Load Regulation, Hold-Up Time And Inrush Current

Prev Page A Look Inside And Component Analysis Next Page Efficiency, Temperature And Noise

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

14 Comments Comment from the forums

Nuckles_56

For such an expensive unit, why on earth did they put the CapXon caps in rather than a complete set of Japanese ones?
Reply
basroil

Wow, this thing has almost as good of regulation and transient responses as the Seasonic 660XP2! And at 1500W no less... Might be a good PSU for not just 4-way K80 workstations, but also powering 12VDC robots too!
Reply
mctylr

Corsair's flagship power supply unit (PSU) offering, the AX1500i, is the best PSU money can buy today, according to many experts in the field.

Honestly?! Do you believe that anyone can reasonably assume that this is an impartial, unbiased review when that is the review's opening?

Argument from authority (or appeal to authority) isn't what I expect from a Tom's Hardware review.
Reply
Bossyfins

Corsair's flagship power supply unit (PSU) offering, the AX1500i, is the best PSU money can buy today, according to many experts in the field.

Honestly?! Do you believe that anyone can reasonably assume that this is an impartial, unbiased review when that is the review's opening?

Argument from authority (or appeal to authority) isn't what I expect from a Tom's Hardware review.

He said to many others in the field. Pretty sure he is not implying himself.
Reply
jimmysmitty

16665297 said:
For such an expensive unit, why on earth did they put the CapXon caps in rather than a complete set of Japanese ones?

They are polymer caps, as mentioned, which might not make a difference even if they went with Japanese caps. In fact looking at the results even some that probably have all Japanese caps got beaten in many areas.
Reply
Eggz

Good review, but please do something about the large arrows blocking the garphs' labels. I can't read what the data actually presents with that info blocked.

As for the actual unit, we know it's good. This thing's been out for about a year now. We at least now have conformation from a pretty reliable source, so thanks for that!

And for this:

Argument from authority (or appeal to authority) isn't what I expect from a Tom's Hardware review.

What is wrong with appealing to authority? I don't know astrophysics, but I can tell you something about it if an astrophysics professor tells me about it. And how would the professor learn his basic knowledge before becoming a professor? Text books, probably. Who wrote those? Ah, yes authorities in the field!

Dismissing references to authorities, as a non-expert, is stupid. It's essentially saying "Since this person has dedicated his (or her) entire life to researching this topic, I will definitely make up my mind on that topic without considering what he (or she) has to say about it." That falls right under the definition of intentional ignorance.

To be fair, though, the article didn't cite to an actual authority. It assumed that the readers will have familiarity with other rigorous review sites like Jonny Guru, who reviewed the AXi1500 back in April of 2014, giving it the only 10/10 ever with the following comment: http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=378

I was starting to think nobody would ever send me a unit good enough. People, THIS is what it takes to get a perfect total score from me. Might be the last time you see it, too. Goes without saying I need to slap in that good old recommended logo right here

Reply
mctylr

16667641 said:

Argument from authority (or appeal to authority) isn't what I expect from a Tom's Hardware review.

What is wrong with appealing to authority? I don't know astrophysics, but I can tell you something about it if an astrophysics professor tells me about it.
Dismissing references to authorities,

Argument from authority is not about presenting or relaying knowledge from a known authority, but the premise that the argument(*) should be accepted on the basis that it came from an authority, not that the argument should be evaluated and (conditionally) accepted based on its own merit.

(*) or in this context a review
Perhaps I was sloppy in my usage. My concern is that by making such a reference to unspecified experts' opinions, introduces a potential cognitive bias, namely that the reviewer (Aris) expected the review unit to perform to those expectations, and not necessarily report with an impartial review of the unit as received and as actually measured.

While I assume the power supply is of excellent quality, and I have no reason to expect any intentional or deliberate wrong-doing, the opening of a review with such a reference of praise, suggests that they reviewer could be subtlety influenced by these expectations during the review process.

In my opinion such a reference to other reviews / opinions does not belong in a review introduction, but if mentioned it should be brought up during the conclusion of the review.

Reply
Amdlova

I see some corsair s... inside its not better than an evga power, Seasonic all for the win!
Reply
iam2thecrowe

16667294 said:
16665297 said:
For such an expensive unit, why on earth did they put the CapXon caps in rather than a complete set of Japanese ones?

They are polymer caps, as mentioned, which might not make a difference even if they went with Japanese caps. In fact looking at the results even some that probably have all Japanese caps got beaten in many areas.

Here's some opinions of capxon caps: http://www.badcaps.net/forum/showthread.php?t=20979
I know I wouldnt trust them, have seen too many blow, and theres really no reason to cheap out on such a high end psu. But, the reason they used them may have been due to sizing, availability of those specs or something else....... They might measure well when theyre new, but will they last?..... This is something a review can never tell us unfortunately. I guess as long as theyre rated generously, they should be ok, polymer caps will have much less tolerance to overvoltage.
Reply
Eggz

16668249 said:

My concern is that by making such a reference to unspecified experts' opinions, introduces a potential cognitive bias, namely that the reviewer (Aris) expected the review unit to perform to those expectations, and not necessarily report with an impartial review of the unit as received and as actually measured.

That's a fair concern generally, but the reasons giving rise to it seem misplaced. The particular place in a review that someone gives praise - beginning, middle, or end - doesn't make much of a difference for anyone who edits their writing, which I'm sure this reviewer does. It's actually good practice to open with lessons learned for this type of article; otherwise, the piece would be meandering and simply take readers through the experimentation process in real time. That's boring and would probably decrease readership.

As for whether to mention (or allude to) other reviews at all, I am not sure it's a good idea for Tom's reviewers to intentionally ignore other reputable reviewers. In all likelihood, many of them are acquaintances from various trade shows. But more importantly, I'd expect a Tom's reviewer to have read all other serious reviews before writing his own. Without doing that, they'd run the risk of writing repetitive information, or worse, writing a less informative review than others currently available. Being familiar with the work of others in your field is part of what builds credibility.

I'm not trying to say that we should pretend Tom's is immune to fallacious logic. It's good to think about those things. My point is just that it didn't seen to present a real problem here.
Reply

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Corsair AX1500i Titanium PSU Review

Today, we're taking a look at Corsair's flagship power supply unit. The AX1500i is a digital, 1500 watt, 80 PLUS Titanium-rated beast of a PSU!