Corsair AX1500i Titanium PSU Review

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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!

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Pros, Cons And Final Verdict

Our test results put the AX1500i at the top of our charts with a significant lead over the second-best PSU ─ Super Flower's superb Titanium unit with 1600 W capacity. The kind of performance the AX1500i offers raises the bar high for the competition and shows the potential of digital control. The key performance features of this PSU are almost perfect load regulation, even under very tough conditions; very high efficiency levels; excellent ripple suppression; and a very long hold-up time. Besides that, the AX1500i has an extremely quiet overall operation, not only for a unit of such high capacity, but also in comparison with other lower-capacity PSUs. The decreased thermal loads ─ thanks to the highly efficient platform ─ along with the quality FDB fan and the optimal fan profile offer low output noise. And at light loads the PSU will operate in a passive mode, and will be completely inaudible.

The cherry on top is the Corsair Link software through which the user can monitor the PSU and gather useful information about its status and functionality in general. In addition, the same software application allows  control of the fan's operation along with the activation of the Over Current Protection on the PCIe and EPS connectors at levels the user wants. We also found the logging capability of this software very useful and we were happy to see that its stability has been hugely improved, compared with older versions.

The only thing we would like Corsair to fix is having to terminate the Corsair Link application and start it up again every time that the PSU is put on standby and reactivated. This might not pose any real-life problems, since when the PSU is on standby the system that feeds it power will be deactivated, and so Corsair Link won't be running. However, if you monitor or control the PSU through another PC, then this can be frustrating.

We would also like to see improved accuracy in the software, especially in the wattage and efficiency readings. Finally, we noticed that from a level of amperes around 4.5 A - 5 A and below, the Corsair Link app shows zero ampere readings on the PCIe and EPS connectors. This most likely has to do with a software/firmware bug that should be fixed.

PSUs like the AX1500i show the potential and the future of digital circuits and the results are very promising. The only downside is the increased cost compared with analog circuits. However, as the production of digital PSUs increases, the costs will be suppressed, allowing for more affordable prices. Another major advantage of digital platforms is the ability to receive and send data to the PSU; thus besides monitoring, the user is also able to control the functions of the PSU. In this case, Corsair doesn't offer many control functions and we would like to have the ability to adjust the voltages of the rails. It is hoped they will add this functionality in the near future. This feature surely doesn't address the average user. But we believe that the ones who will invest their money in a PSU like the AX1500i belong to the enthusiast category, and hence, they will appreciate a voltage control functionality through the Corsair Link app.

 To sum up, we believe that the AX1500i is the best PSU money can buy today, and if you need such high-power levels and can pay the price, then you should put it at the top of your buying list. Its only true competitor is the Super Flower Leadex Titanium PSU with 1.6 kW capacity, which doesn't use a digital platform, isn't as quiet, and its performance, although very high, cannot reach the AX1500i's levels.

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Aris Mpitziopoulos is a Contributing Editor for Tom's Hardware, covering Power Supplies.

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Aris Mpitziopoulos
Aris Mpitziopoulos
Contributing Editor

Aris Mpitziopoulos is a contributing editor at Tom's Hardware, 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