Introduction
HuntKey has just rolled out a major hardware refresh for its AX850P Trident PC power supply from the Heavy Firepower series, upgrading the pre-stage PFC boost circuit with third-party GaN power devices in place of traditional silicon MOSFETs. This transition slashes conduction and switching losses in the PFC stage to achieve up to 92% peak efficiency, cementing its status as a top-tier 850W power solution built for enthusiast builders and entry-level AI rigs.
Beyond its GaN core architecture, the unit fully embraces the latest ATX 3.1 power standards and natively integrates a PCIe 5.0 high-wattage graphics connector. A robust single +12V rail churns out a massive 70.8A for 849.6W of continuous muscle, effortlessly handling the aggressive transient power spikes of modern flagship RTX 40 and upcoming 50-series GPUs.
Tackling the real-world gripes of high-end system builders, HuntKey pulls out all the stops with meticulous cable management, advanced thermal design, quiet acoustics, and comprehensive safety protections—backed by an impressive 7-year warranty. Let's dive in for a closer look at what makes this PSU tick.
Product Appearance
The box proudly displays the HuntKey logo, product image, model name, 80 PLUS Platinum certification badge, and major callouts like GaN tech and ATX 3.1, laying out key specs right on the cover.
The bottom lists ten core features, detailed specs, and manufacturer info.
Inside are the modular cables, along with a user manual, cable ties, and cable combs.
The snake-pattern modular cables use an embossed PVC finish for greater flexibility and easier cable routing, while also giving the finished build a cleaner look.
High-purity tinned copper conductors meet UL standards and are paired with high-current phosphor bronze terminals for reliable power delivery.
It keeps a familiar overall design and comes in black and white.
A dual-ball-bearing fan is mounted on top, with temperature-controlled operation for lower noise.
The power supply label is located on the side.
Model: HK950-56PP
AC Input: 100-240V~, 50-60Hz, 10-5A
DC Output: +12V ⎓ 70.8A, +5V ⎓ 25A, +3.3V ⎓ 25A, -12V ⎓ 0.5A, +5VSB ⎓ 2.5A
Rated Power: 850W
Manufacturer: Shenzhen Huntkey Electric Co., Ltd.
The power supply has obtained CCC certification and complies with China RoHS requirements.
The AC input end features an IEC power inlet and a power switch.
The modular interface on the opposite side is arranged in two rows. The top row serves CPU, 8-pin GPU, and PCIe 5.0 power connections, while the lower row handles storage and mainboard power.
The length of the power supply is about 150.3mm (5.917 inches).
The width of the power supply is about 150.1mm (5.909 inches).
The length of the power supply is about 86.11mm (3.390 inches).
The weight is about 1395g (49.207 oz).
Teardown
With the exterior walkthrough of the HuntKey AX850P ATX 3.1 Platinum GaN power supply covered, we now move on to the teardown to see what is inside.
Unscrewing the enclosure reveals a 3D thermal design with a clear airflow path designed to efficiently carry heat out of the PSU.
The cooling fan connects to the PCBA module through a plug-in connector for convenient assembly.
The fan is from Yate Loon, model D12BH-12, rated at 12V 0.6A.
With the PCBA removed, Mylar insulation sheets can be seen along the bottom and sides.
Thermal putty transfers heat from the MOSFETs to the metal enclosure, effectively turning the chassis into a large heatsink.
The wires connecting the power inlet to the PCBA pass through a ferrite core for interference suppression.
The safety X2 cap is wrapped with insulation tape and secured with potting compound, while its leads are sleeved with insulating tubing.
A Y-cap is also soldered in place, which is from SHM, model E102M.
Another Y-cap.
On the front of the PCBA module, the AC input end is located at the upper-left corner and includes a fuse, Y-caps, common-mode chokes, safety X2 cap, relay, and NTC thermistor. The heatsink carries the bridge rectifiers, PFC switching MOSFETs, PFC rectifier diodes, and LLC switching MOSFETs. The right side also contains a film filter cap, PFC boost inductor, high-voltage electrolytic filter caps, resonant cap, and resonant inductor.
A modular PCB is soldered along the lower section. The center contains the master control chip, transformer, standby power control chip, and standby power transformer, while the left side contains filter caps and the 3.3V/5V synchronous buck circuits.
High-current traces on the back use exposed copper with added solder, along with soldered copper reinforcement plates for higher current capacity.
The input fuse is from WALTER, rated at 10A 250V.
The blue Y-cap is marked AB102M.
The common-mode chokes are wound with enameled wire, with phenolic insulating sheets underneath. A CARLI safety X2 cap is positioned between them.
The safety X2 cap is rated at 0.22μF.
The relay and NTC thermistor are reinforced with potting compound.
The NTC thermistor is from JOYIN, model 15S070L, and is used to suppress inrush current at power-on.
One bridge rectifier is mounted on each side of the heatsink and secured with screws.
The bridge rectifier is from GULFSEMI, model GBU10K, rated at 800V 10A and housed in a GBU package.
The film filter cap is from CARLI, rated at 2.2μF 450V.
The master control chip is from NXP, marked HKP6288AT, which is an integrated PFC + LLC controller that combines a PFC controller, LLC controller, and gate drivers in a single device, and is housed in an SO16 package.
The filter cap supplying power to the master control chip is from AiSHi, rated at 50V 22μF.
The PFC switching MOSFET is from Innoscience, model ISG6122ATD, which is a SolidGaN co-packaged device integrating a high-performance enhancement-mode GaN power transistor, with a continuous rated voltage of 650V, an on-resistance of 27mΩ, a transient withstand voltage of up to 800V, and a maximum switching frequency of up to 2MHz.
It integrates a high-precision LDO gate-clamp circuit and supports a 10-24V drive voltage range. It also features an integrated Miller clamp to effectively suppress false turn-on during high-speed switching. Separate external turn-on and turn-off resistors can be used to flexibly adjust the switching slew rate, helping optimize both EMI performance and conversion efficiency. It also integrates a 20ns input deglitch filter and supports a minimum output on-pulse width of 100ns. With zero reverse-recovery charge, the device also supports parallel operation.
The ISG6122ATD is suitable for high-power switching power supplies, AC-DC, DC-DC, and DC-AC converters, totem-pole PFC, LLC resonant converters, half-bridge and full-bridge converters, data center and AI server power supplies, air conditioners, photovoltaic inverters, motor drives, onboard chargers (OBCs), and automotive DC-DC converters. It is housed in a TO-247-4L package.
The PFC boost inductor is wound with enameled wire, with a phenolic insulating sheet underneath and reinforced with potting compound for secure mounting.
The PFC rectifier MOSFET is from PNJ, model P3D06006T2, which is a SiC Schottky diode rated at 650V 6A and housed in a TO-220-2 package. It is suitable for applications such as PFC and switching power supplies, helping reduce reverse-recovery losses and switching noise while improving conversion efficiency.
The high-voltage filter cap is from Nichicon.
The cap is rated at 560μF 450V.
The blue Y-cap is marked AB102M.
The two LLC switching MOSFETs share the same model and are secured with screws, with thermal pads placed between them and the heatsink.
The LLC switching MOSFET is from Sanrise, model SRC60R075BS, NMOS, 600V and 75mΩ, and housed in a TO-220C package.
The resonant cap is rated at 0.1μF 630V, while the resonant inductor on the left is wound with Litz wire.
The resonant inductor.
The transformer core is tightly wrapped with insulation tape.
The copper-strip transformer uses red-copper windings, whose thermal conductivity is second only to silver, and adopts a high-temperature-resistant 155°C LASSF design. It provides ample design margin and offers good resistance to damage and corrosion.
Copper reinforcement plates are soldered to the back of the PCB beneath the transformer area to increase current-carrying capability.
The standby power supply chip is from INFSitronix, model IN2P380C, which integrates a 650V power switch and is housed in an SOP-8 package.
The standby power transformer is wrapped with insulation tape.
The Everlight EL817 optocoupler is used for feedback control.
The other two optocouplers share the same model.
The supervisory control chip is from NDP, model NDP5201KC, housed in an SOP-8 package.
The synchronous rectifier controller and the six synchronous rectifier MOSFETs arranged on both sides.
The synchronous rectifier controller is from NXP, model TEA2095, which is a dual-channel SR controller integrating two gate drivers, allowing it to drive two synchronous rectifier MOSFETs simultaneously while also supporting independent operation. It is designed for LLC resonant power supplies and is housed in an SO8 package.
All six synchronous rectifier MOSFETs are from CRMICRO, model HGQ014N04B-G, NMOS, 40V and 1.1mΩ, designed for synchronous rectification applications and housed in PDFN5×6-8L packages.
The power supply output end, which includes solid-state filter caps, a filter inductor, a synchronous buck controller, synchronous buck switching MOSFETs, and buck inductors.
The solid-state filter caps are from SAMXON, belonging to the ULR series. Each is rated at 16V 680μF, with eight caps used in total.
The solid-state filter cap is from Elite, belonging to the UGS series aluminum polymer cap family, rated at 2200μF 16V.
Six solid-state filter caps rated at 6.3V 1000μF are used.
The synchronous buck controller for the 3.3V and 5V rails is from ANPEC, model APW7159C, which is a dual-channel synchronous buck controller featuring excellent output voltage regulation, integrated soft-start, and a patented soft-off function. It also integrates bootstrap diodes and supports output OVP, output UVP, and OTP. It is housed in an SOP-20 package.
The two sets of synchronous buck MOSFETs correspond to the two output rails.
All four synchronous buck switching MOSFETs are from CRMICRO, model HGQ022N03A, NMOS, 30V and 1.6mΩ, and are housed in PDFN5×6 packages.
Two 3.3μH buck inductors.
A modular PCB is installed at the output end, with copper reinforcement plates soldered to increase current-carrying capability, with solid-state caps used for output filtering.
The synchronous buck converter is from NDP, model NDP2431KC, housed in an SOP-8 package.
Six SAMXON ULR series solid-state filter caps rated at 16V 330μF are used.
A total of five 6.3V 470μF solid-state filter caps are used.
Five SAMXON UER series solid-state filter caps rated at 16V 100μF are used.
The copper reinforcement plates soldered to the PCB to increase current-carrying capability.
Well, those are all components of the Huntkey AX850P 850W ATX 3.1 80 PLUS Platinum GaN Power Supply.
Summary of ChargerLAB
From an installation perspective, the Huntkey Heavy Firepower AX850P Platinum GaN power supply comes equipped with fully modular braided soft cables that strike an ideal balance between flexible cable routing and electrical safety. Featuring a native PCIe 5.0 high-wattage GPU connector along with generous CPU and peripheral modular terminals, it easily facilitates multi-hardware system expansions. A 100-240V wide-range AC input accommodates varied domestic power grids, while its 850W continuous rating and massive single-rail +12V output effortlessly handle the power requirements of high-end gaming rigs, entry-level AI workstations, and multi-drive storage systems.
A full teardown exposes a mature core topology built on an active PFC, resonant LLC, and synchronous DC-DC architecture. Retaining the primary NXP HKP6288AT digital controller scheme, HuntKey integrates Innoscience SolidGaN ISG6122ATD devices to execute a targeted upgrade of the PFC circuit—directly targeting high-loss and high-heat bottlenecks to deliver noticeable gains in energy efficiency and thermal management for a cooler, quieter, and more efficient operation.
Furthermore, the primary high-voltage stage utilizes Japanese Nichicon bulk caps, complemented by robust multi-layer solid-state filtering throughout the primary and secondary stages. Rounded out by a 12cm intelligent Yate Loon cooling fan, an optimized 3D airflow duct, and thermal putty casing integration, the entire unit showcases a top-tier specification sheet from AC input to DC output, cementing its reputation as a ruggedly engineered, highly reliable power supply.