Corsair AX1000 PSU Review: Titanium-Class Efficiency At A Premium Price

Corsair's AX1000, along with the 80 PLUS Platinum- and Titanium-rated Seasonic Prime models, are currently the best 1kW PSUs that money can buy. The recently refreshed AX family consists of high-performance 1000W and 850W models, which are ideal for enthusiasts with power-hungry hardware they want to overclock. Both PSUs are based on the amazing Seasonic Prime Titanium platform. And although this is an analog design, it still sets an example for digital platforms to follow.

The AX1000 is not an inexpensive power supply; it mostly caters to builders who view their PSU purchase as an investment. Shouldn't we all think that way, though? After all, your PSU is the heart of your PC.

At least for the time being, there is no 1000W model in the AXi family. The AX1000 plays alone, followed by the lower-rated HX1000 and HX1000i in Corsair's portfolio.

On the other hand, the AX850 looks similar to the AX860i. It lacks a digital interface, but offers a better efficiency classification, partially justifying a higher price.


Manufacturer (OEM)Seasonic
Max. DC Output1000W
Efficiency80 PLUS Titanium, ETA-A+ (91-94%)
NoiseLAMBDA-A (20-25 dB[A])
Modular✓ (Fully)
Intel C6/C7 Power State Support
Operating Temperature (Continuous Full Load)0 - 50°C
Over-Voltage Protection
Under-Voltage Protection
Over-Power Protection
Over-Current (+12V) Protection
Over-Temperature Protection
Short Circuit Protection
Surge Protection
Inrush Current Protection
Fan Failure Protection
No Load Operation
Cooling135mm fluid dynamic bearing fan (HA13525M12F-Z)
Semi-Passive Operation✓ (selectable)
Dimensions (W x H x D)152 x 87 x 172mm
Weight2.06 kg (4.54 lb)
Form FactorATX12V v2.4, EPS 2.92
Warranty10 years

Power Specifications

Max. PowerAmps25258330.3
Total Max. Power (W)1000

Cables & Connectors

Modular Cables
DescriptionCable CountConnector Count (Total)GaugeIn Cable Capacitors
ATX connector 20+4 pin (610mm)1116-20AWGYes
4+4 pin EPS12V (650mm)2218AWGYes
6+2 pin PCIe (670mm+100mm) 4816-18AWGYes
SATA (460mm+110mm+110mm+110mm)41618AWGNo
Four-pin Molex (450mm+100mm+100mm+100mm)2818AWGNo
FDD Adapter (110mm)1122AWGNo
AC Power Cord (1400mm)1114AWG-

This is a fully modular PSU with fairly long cables. With that said, we'd expect the distance between peripheral connectors (especially the four-pin Molex ones) to be greater. Moreover, the EPS connectors should utilize thicker wires for lower voltage drops under high loads.

The number of SATA connectors is amazingly high, and it is nice to get so many four-pin Molex connectors as well. There's even a bundled Berg adapter for enthusiasts who still need a FDD connector.

Component Analysis

General Data
Manufacturer (OEM)Seasonic
Platform ModelPrime
Primary Side
Transient Filter6x Y caps, 3x X caps, 2x CM chokes, 1x MOV
Inrush ProtectionNTC thermistor & relay
Bridge Rectifier(s)2x Vishay LVB2560 (600V, 25A @ 105°C)
APFC MOSFETs2x Infineon IPP60C7099 (650V, 14A @ 100°C, 0.099Ω)
APFC Boost Diode1x STPSC10H065D (600V, 10A @ 135°C)
Hold-up Cap(s)1x Hitachi (400V, 470uF, 2000h @ 105°C, HU)
1x Hitachi (400V, 820uF, 2000h @ 105°C, HU)
Main Switchers4x Infineon IPP50R140CP (550V, 15A @ 100°C, 0.14Ω)
Drivers For Main Switchers2x Silicon Labs Si8230BD
APFC ControllerON Semiconductor NPC1654
Switching ControllerChampion CM6901
TopologyPrimary side: Full-bridge & LLC resonant converter
Secondary side: Synchronous rectification & DC-DC converters
Secondary Side
+12V MOSFETs6x Nexperia PSMN1R0-40YLD (40V, 280A @ 25°C, 1.4 mΩ)
5V & 3.3VDC-DC Converters: 6x Infineon BSC0906NS
PWM Controller: APW7159
Filtering CapacitorsElectrolytics: Nippon Chemi-Con (105°C, W, KZE, KYB), Nippon Chemi-Con (4000-10,000h @ 105°C, KY), Rubycon (3-6000h @ 105°C, YXG), Nichicon (5000-6000h @ 105°C, HV)
Polymers: FPCAP, Nippon Chemi-Con
Supervisor ICWeltrend WT7527V (OVP, UVP, OCP, SCP, PG ) & AS393M
Fan ModelHong Hua HA13525M12F-Z (135mm, 12V, 0.36A, 1800 RPM, fluid dynamic bearing)
5VSB Circuit
Buck ConverterLeadtrend LD7750R
RectifiersSTMicroelectronics STU6N65K3 (650V, 3A @ 100°C, 1.3Ω)
Infineon BSC0906NS (30V, 40A @ 100°C, 4.5 mΩ)
-12V Circuit
Buck ConverterLite-On LSP5523 (3A max output current )

The AX1000's platform is the same one used in Seasonic's top-notch Seasonic Prime Titanium (and Platinum) models. It is built using high-quality components from companies like Vishay, Infineon, and Nexperia. In addition to its Japanese electrolytic caps, the secondary side also features a number of polymer capacitors from FPCAP and Chemi-Con.

A fluid dynamic bearing-based cooling fan serves up a longer useful life than lower-cost alternatives. And even though the -12V rail goes unutilized these days, we're still glad to see a proper rectifier used for it instead of a plain diode.

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