The AX1600i is the worthy successor to the legendary AX1500i. Both units are made by Flextronics, using cutting edge technology, while offering the best performance available today thanks to their digital platform.
In addition to being highly efficient, the AX1600i offers excellent load control, excellent transient response, long latency and excellent ripple suppression. Despite its high capacity, it remains quiet thanks to the relaxed fan profile and a high-quality FDB fan. Finally, the Corsair Link software allows you to choose between three fan modes: performance, balanced and quiet, allowing each user to set the PSU according to their needs.
You’ll pay a lot to get your hands on a Corsair AX1600i, but there’s nothing else that can meet this PSU face-to-face when it comes to overall performance. Simply put, it’s the best PSU for gaming (opens in new tab).
Specifications:
| Manufacturer (OEM) | Flextronics |
| Maximum DC output | 1600W |
| efficiency | 80 PLUS Titanium, Cybenetics Titanium |
| Noise | Cybenetics A (20-25 dB[A]) |
| Modular | Yes (full) |
| Intel C6/C7 Power State Support | Yes |
| Operating temperature (continuous full load) | 0 – 50°C |
| Protections | OVP, UVP, OPP, OCP, OTP, SCP, peak |
| Operation without charging | no |
| Cooling | 140mm Fluid Dynamic Bearing Fan |
| Semi-passive operation | Yes |
| Dimensions (W x H x D) | 150 x 85 x 200mm |
| Weight | 2.6kg (5.73lb) |
| form factor | ATX12V v2.4, EPS 2.92 |
| Guarantee | 10 years |
| Price | $500 |
The Corsair AX1600i is the first desktop PSU to use such an advanced technology, which is used by very few PSUs even a few years after its release. Basically, the AX1600i uses a totem pole PFC converter, which uses GAN MODFETs, which can provide up to 99% efficiency compared to the 96% efficiency levels that the most advanced conventional APFC converters can deliver.
In addition to the totem pole PFC, the AX1600i has two Digital Signal Controllers (DSCs) to control its circuitry. A single microcontroller (MCU) is the communication bridge between the system and the PSU, which also allows users to control some vital functions of the PSU (for example, the fan speed profile and selection between multiple and single +12V rails, setting the OCP limits , etc.) in addition to auditing tasks. So far, only Wentai has managed to bring a totem pole PSU to market, but still can’t match the performance levels and reliability of the AX1600i.
The totem pole APFC requires a digital controller, and the AX1600i has two, to handle the APFC converter, the primary and secondary sides. The 12V rail is digitally controlled, while the secondary rails and 5VSB use an analog controller to control the cost and complexity of the design. The build quality is top notch and the cooling fan uses a fluid dynamic bearing for greater reliability. Since this PSU is for extreme systems, Corsair could also use a double ball bearing fan, which is more suitable than FDB fans, for use at high operating temperatures.
Some more details about the total pole APFC that the AX1600i uses and why it offers higher efficiency: In a conventional APFC converter, when the conduction path is turned on, the signal has to pass through two low-speed diodes (from the bridge rectifiers). and a switch. When the conduction path is turned off, the signal goes from two low-speed diodes and one high-speed diode (SBR). In a totem pole PFC, the signal passes through a MOSFET and a MODFET in both cases, so theoretically we have no voltage drops. This is why totem pole PFCs achieve efficiencies of up to 99%, while the most efficient APFC circuits achieve around 96%.
| Rail | 3.3V | 5V | 12V | 5VSB | -12V |
|---|---|---|---|---|---|
| Maximum Power (amps) | 30 | 30 | 133.33 | 3.5 | 0.8 |
| Maximum Power (watts) | 180 | 180 | 1600 | 17.5 | 9.6 |
1600W max power at 12V means this PSU can handle anything you throw at it. The maximum combined power on the secondary rails is also high at 180W. Most PSUs today are limited to 100 to 120W on the secondary rails.
| Cable | Amount included | cable caps |
|---|---|---|
| ATX connector 20+4 pin | 1 | Yes |
| 4+4 pin EPS12V | 2 | Yes |
| 6+2-pin PCIe | 8 | Yes |
| SATA | 5 | no |
| 4-pin Molex (or adapter) | 3 | no |
| AC power cord | 1 | N/A |
Lots of cables and connectors are provided, but there is no 12+4-pin PCIe. Hopefully, Corsair will keep the AX1600i on the market and make it compatible with ATX v3.0, by also adding the new PCIe connector.
Performance
Looking for performance and load regulation is super tight on all rails and ripple suppression is excellent. The bulk caps have enough capacity to provide a long latency even when the PSU is running at full load, and the inrush currents are super low.
Efficiency is high at both normal and light load, especially the 5VSB busbar. The AX1600i puts all other platforms to shame in terms of average efficiency, thanks to its totem pole-APFC converter. The AX1500i was already a tough competitor for the competition; the AX1600i is on another level and leaves no doubt as to who the performance king is.
The transient response is excellent on all rails, especially the minor ones where the AX1600i smokes the competition. At 12V, only the Super Flower Leadex platform has a small cable, without using any digital circuitry.
The digital platform allows OCP adjustments at 12V. The secondary rails are super strong, with OCP set at 130 to 136% of their rated power levels, and the overcurrent protection is at a normal level, allowing the PSU to deliver over 1900W before shutting down.
The high efficiency levels provide a relaxed fan speed profile, which can be custom-tuned via the iCUE software, making the AX1600i one of the quietest high-capacity PSUs available.
Final Thoughts
We hope Corsair can sort things out with Flextronics and update the AX1600i to meet all the new ATX v3.0 requirements. This won’t be as difficult as other analog platforms as firmware changes will allow the PSU’s performance and security features to be tweaked, but it won’t be an easy task either. Once the new GPUs come out, we’ll know for sure whether the PCIe 5.0 connectors will be the new standard or whether the legacy PCIe connector (6+2 pin) will get a life extension. Still, the fact is that eventually the PCIe 12+4-pin connectors will dominate the market, so all PSUs with 450W and above capacity should have them.
The Corsair AX1600i is the best performing PSU on the market today, even several years after its release. Corsair did well to be the first to use GaN MODFETs and the totem pole APFC converter in a desktop PSU and this gamble paid off. If there was a PSU to get close to, it would be the Be Quiet! Dark Power Pro 1500W, but Corsair takes first place here.
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