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.