Introduction

After many years, Corsair has decided to revamp its HXi line with two new units, featuring 1000 W and 1500 W max power. I will look at the flagship model, the HX1500i, utilizing a cutting-edge CWT platform, using digital circuits for its significant functions. The use of digital circuits allows monitoring and control of the HX1500i through Corsair's iCUE application. Besides monitoring the PSU's performance, you can select between single and multiple 12 V rails through software and also set a fan speed profile that meets your needs. I find iCUE to be a bit more complex than required, but it is richly featured, and the ability to have custom fan speed profiles is a vital asset.

The HX1500i is rated as Platinum in the 80 PLUS and Cybenetics schemes, and it also has a Cybenetics A- noise rating, which translates to 25-30 dBA average noise output. Not many high-capacity PSUs can achieve such a noise rating, so the HX1500i is suitable for a quiet gaming system. With 200 mm depth, this is not a small PSU, so you should ensure that your chassis can accommodate it, before spending 400 dollars purchasing the unit. I prefer large PSUs over downsized ones, which can be noisier due to restricted airflow in their internals. The use of large fans also helps in keeping the noise low.

You won't find 12VHPWR connectors in the HX1500i's bundle, but this is not a problem since you can order one from Corsair. Moreover, NVIDIA made it clear that there is no need for ATX 3.0 and PCIe 5.0 compatible PSUs for its Ada Lovelace GPUs. PSUs following the ATX 2.53 guideline and with the appropriate capacity won't have a problem powering the upcoming GPUs by using adapters. I suggest you get at least a 12+4 pin cable and avoid using adapters. It seems NVIDIA has fixed the power spike issues that we noticed in the RTX 3000 series products, and the new DC-DC converters apply less stress to the power supply. This is good news for all consumers, most of whom won't have to replace their power supply, not yet at least.

Specifications

Photos

The large box has a photo of the PSU on its face, showing the modular panel, which is fully covered by sockets.


Foam spacers protect the PSU inside the box. A smaller box within contains all cables.


The bundle includes a safety leaflet, fixing bolts, and zip ties. As usual, for a Corsair sample, there is a USB flash drive containing the detailed performance report.


We find triangular perforations, Corsair's most recent design trend in PSUs.


Stickers with the model number are on the sides, and the power specification label is on the bottom.


The modular panel is fully occupied by connectors since 1500 W requires lots of cabling to pass through the load through smoothly. There is also a Type-C socket for connection to the system.


Measuring 200 mm in depth, this PSU has a large footprint.


Here are some more photos of the PSU from various angles.

Cables and Connectors

There are plenty of cables and connectors, and thankfully there are no in-cable capacitors, which might help to offer lower ripple, but make the cables much less flexible, thus harder to route.


The distance between the peripheral connectors should be longer, at 150 mm.

Component Analysis

Before reading this page, we strongly suggest looking at this article, which will help you better understand the insides of a PSU.



Corsair used a CST platform as the base for its modifications. The design is modern, since digital controllers handle most circuits, and the build quality is top notch. Vishay and Infineon provide the FETs, while the capacitors are by Chemi-Con, Rubycon, and FPCAP. You cannot ask for more in a desktop PSU. On the primary side, an interleaved PFC is used for higher efficiency, and the full bridge topology is supported by an LLC resonant converter. On the secondary side, we find synchronous rectification and DC-DC converters for the generation of the minor rails.


The transient filter has all the necessary parts to suppress EMI emissions.


The discharge IC isolates the bleeding resistors from the X caps, providing a small efficiency boost.


There is an MOV for protection against power surges. An NTC thermistor handles inrush currents. A bypass relay supports the latter.


The pair of bridge rectifiers can handle up to 50 Amperes.


The interleaved APFC converters use two Infineon FETs and a pair of CREE boost diodes. The bulk caps are by Chemi-Con and have above 400 V voltage ratings.


The primary switching FETs are installed into a full-bridge topology, ideal for high power output.


All digital controllers and the unit's MCU are installed on a large daughter board.


Because of space restrictions, CWT used two smaller parallel transformers instead of a single, huge one.


12 Vishay FETs regulate the +12 V rail. They are installed on a board adjacent to the main transformers.


The VRMs handling the minor rails are among the few circuits in this PSU that use analog controllers.


The filtering caps are of high quality, both electrolytic and polymer ones.


The standby PWM controller is an On Bright OB5282CP IC.


Sockets fully occupy the modular PCB.


Soldering quality is good.


Some close-up photos of the main PCB.


The cooling fan uses a fluid dynamic bearing. This Corsair fan has proved its reliability through the years. It looks weird, though, that the lower grade in Corsair's portfolio of products, the RMx line, uses ML fans, which are considered of higher quality than FDB fans. Most likely, the latter provide lower noise output and are not so hard to make; hence their production cost is lower.

Test Setup