The demand for small form factor gaming PCs continues to grow, leading manufacturers to develop more compact and efficient power supply options. GAMEMAX has been expanding in this segment with products aimed at builders who need reliable performance in tighter enclosures. After reviewing the larger GX-1050 PRO ATX 3.1 PSU, the focus now shifts to the GS Series of SFX Gold power supply.
The GAMEMAX GS Series SFX Gold lineup includes 650 W, 750 W, and 850 W models. Our focus is on the GS 850W (White), an ATX 3.1-compliant unit that integrates a native 12V-2×6 connector for the latest NVIDIA graphics cards. Available in both black and white, it is designed to fit compact builds without compromising on compatibility.
Internally, the GS Series uses Japanese capacitors and incorporates Active PFC, Half-Bridge LLC Resonance, Synchronous Rectification, and DC-DC topology. These components and design choices target stable output across all rails. The unit carries an 80 Plus Gold certification, with efficiency levels above 90% under typical loads. Cooling is managed by a hydraulic bearing fan, rated for 40,000 hours of use, which remains inactive below 20% load to reduce noise.
The PSU includes a complete set of protections—OVP, UVP, OPP, OCP, SCP, OTP, and SIP—to safeguard both the unit and connected components. A fully modular design, combined with a 90° angled 12V-2×6 connector, also helps with cable management in space-limited cases. This review takes a closer look at how the GAMEMAX GS Series SFX Gold 850W performs in practical conditions, examining efficiency, thermal behavior, and overall reliability in compact gaming and workstation builds.
Specifications
| Specification | Details |
|---|---|
| Dimensions (W x H x D) | 125 mm × 63.5 mm × 110 mm |
| Input Voltage | 110–240 VAC |
| Input Current | 10–5 A |
| Input Frequency Range | 50–60 Hz |
| PFC | Active PFC (>0.99) |
| Power Good Signal | 100–150 ms |
| Hold Up Time | >10 ms |
| Efficiency | >87% (92% max) |
| MTBF | >100,000 hours |
| Protection | OPP / OVP / UVP / OCP / SCP / OTP / NLP / SIP / OLP / NLO |
| Power | 850 W |
| Operating Temperature | 0–40 °C |
| Safety Certifications | CE / FCC / CB / ROHS / TUV / cTUVus |
| Cooling | 90 mm Ultra Silent Fan |
| Noise Level | <25 dBA |
| 80 Plus Certified | Yes – 80 Plus Gold |
Unboxing
The GAMEMAX GS Series power supply comes in a compact white box with a simple but informative layout. On the front, the model name, 80 Plus Gold certification, and 850W rating are displayed with a reflective finish, alongside icons for PCIe 5.1 and ATX 3.1 compatibility and a 10-year warranty label. The back of the packaging lists detailed specifications, covering AC input (110–240V, 50–60Hz, 10A) and DC output values for the GS 850G WH, GS 750G WH, and GS 650G WH models. It also outlines available connections, including main power, CPU, PCIe, SATA, and peripheral connectors, giving buyers a clear view of the unit’s capabilities before unboxing.
Opening the box, the GAMEMAX GS Series power supply is well protected in thick white foam to keep it safe during transport. The modular cables are placed in a separate grey storage bag for easy handling and organization. Along with the unit and cables, the package includes four mounting screws, two cable ties, and a user manual, providing the necessary items for installation.
Design
The GAMEMAX GS Series power supply uses a standard SFX layout at 125 x 63.5 x 110 mm, making it a practical option for ITX cases where space is limited. The unit is offered in both black and white, with this review focusing on the white edition. Its exterior has a uniform finish, with the top cover and fan grille blending into a single design. The grille follows a hexagonal pattern with wide openings to support airflow and cooling performance. At the center of the fan, the GAMEMAX logo adds a clear but subtle mark of branding that fits the overall clean appearance.
The GS Series uses a 9.2 cm hydraulic bearing fan with a slim 15 mm frame, designed to balance cooling efficiency with compact dimensions. Its PWM-controlled start/stop function keeps the fan off when the load is low and spins it up once power consumption rises above 20%, helping to keep noise levels below 25 dBA. With nine blades and a narrow bezel, the fan provides a larger surface area for airflow, improving cooling performance without increasing the overall footprint.
The PSU carries a clean layout with its specifications label located on the bottom side. It provides clear details of the AC input range of 100–240V at 50–60Hz, while the DC outputs are rated for +3.3V and +5V at 15A each, a +12V rail delivering up to 70A (840W), +5VSB at 2.5A, and -12V at 0.3A. The unit is rated for a total of 850W. The label also includes the 80 Plus Gold certification along with CE, CB, TUV, and RoHS markings, giving users essential information about efficiency and compliance at a glance.
The GameMax GS Series Gold SFX power supply features a practical modular design that makes installation and cable management easier. The connector arrangement is well laid out, with the top row dedicated to the motherboard, CPU/PCIe, and dual 12V 2×6-pin connectors that provide up to 600W for the latest graphics cards. The middle section offers several peripheral and SATA connectors, supported by temperature control to maintain consistent performance. The lower row includes extra CPU/PCIe outputs, adding flexibility for high-end processors and GPUs. This design approach ensures reliable power distribution while keeping the build organized and efficient.
The rear side of the power supply uses a perforated grille to help with airflow and cooling. At the center, the AC input port is clearly marked for 100–240V support, making it compatible with different power standards. A power switch is positioned just below the port, giving users direct control when shutting the unit off. Mounting holes along the sides provide a secure fit inside a PC case, while the overall layout is clean and practical.
The GS Series SFX PSU’s right and left side panels showcase a holographic lion logo, shifting colors depending on the angle of light. Its 850W rating is displayed in bold holographic text, making the power capacity easy to identify. The surface carries a repeating “G” and “S” pattern tied to the Gamemax branding, adding a modern touch to the overall look. Perforated areas are integrated into the design, hinting at the ventilation system inside while maintaining a clean and uniform appearance.
Internal Components
The GS 850G WH is a fully modular 80 PLUS Gold certified power supply that delivers over 90% conversion efficiency under typical loads. Built with Japanese 105°C electrolytic and solid capacitors, it is engineered for long-term stability and consistent performance. The flat transformer design, gold-plated pins, and high-density copper posts help minimize internal wiring, improve heat dissipation, and maintain clean airflow within the system. These design choices are aimed at ensuring reliable power delivery while reducing electrical noise.
For protection, the GS Series SFX PSU WH covers all major safeguards, including over-voltage, under-voltage, over-current, over-power, short-circuit, and over-temperature defenses. At its core, the unit uses the MPS1213 programmable LLC controller to maintain efficiency across different load conditions. In addition, a dedicated microcontroller manages smart fan start/stop functionality, keeping operation quiet during low-demand scenarios while ramping up cooling when needed. Together, these features make the GS 850G WH a capable option for modern PC builds where efficiency, safety, and reliability are important.
Cables and Connectors
The GS Series SFX PSU comes with a fully modular cable system, allowing users to connect only the cables their build requires. This helps maintain a clean layout and improves case airflow, which is especially useful in smaller cases where space is limited. Each connector port is labeled with clear white text, making installation easier and reducing the chance of mismatched connections.
The cable set features a flat, all-white design and includes the following options:
| Cable Type | Connector(s) | Length (mm) | Quantity | Remarks |
|---|---|---|---|---|
| Motherboard | 24+4-pin | 350 + 100 | 1 | Main ATX power for motherboard |
| CPU | 4+4-pin (x2) | 400 + 100 | 1 | For CPU power delivery |
| PCIe | 6+2-pin (x2) | 400 + 150 | 2 | For discrete GPUs |
| PCIe (12V) | 2×6-pin | 400 + 100 | 1 | For high-power GPU setups |
| SATA | 3 connectors | 300 + 150 + 150 | 2 | For SSDs, HDDs, and peripherals |
| IDE (Molex) | 3 connectors | 300 + 150 + 150 | 1 | For legacy devices/accessories |
| GPU (Next-Gen) | 12VHPWR (12+4 pin) | — | 1 | For modern GPUs (ATX 3.1 / PCIe 5.1) |
With an output of 850W, the PSU provides sufficient headroom for modern components, including high-performance graphics cards. The separate PCIe cables offer reliable power delivery, while the inclusion of the 12VHPWR connector supports the latest GPUs. This connector uses a 12+4 pin layout, with 12 main power lines and four additional signal pins. The signal pins communicate with the GPU to regulate power draw if the PSU cannot meet its full demand. While this function protects hardware, it can also limit GPU performance in some cases.
The 90-degree angled connector makes installation easier, offering a sturdier fit while improving cable management inside compact or high-airflow cases.
The selection of cables covers the needs of most gaming and workstation builds, while compliance with ATX 3.1 and PCIe 5.1 standards ensures compatibility with current and upcoming hardware.
Performance & Testing
The GAMEMAX GS Series SFX Gold 850W was tested with a high-end configuration to measure its efficiency, thermal control, and stability under load. The test system featured an Intel Core Ultra 7 265K processor, Maxsun iCraft Z890 Arctic motherboard, 32 GB of DDR5-8000 memory, and an AORUS RTX 4080 SUPER MASTER graphics card. This configuration represents a demanding scenario for compact gaming and workstation builds, allowing us to assess efficiency, voltage stability, and thermal management under real-world conditions.
Efficiency
The PSU maintained efficiency above 90% across typical loads, peaking near 92% around 50% load. These results are consistent with its 80 Plus Gold rating and indicate low energy loss, which benefits both electricity usage and system stability during extended gaming or productivity sessions.
Voltage Stability
Voltage regulation remained steady across all rails. The +12V line, critical for CPU and GPU performance, fluctuated by less than 1% even under full load. The +5V and +3.3V rails were stable, meeting ATX standards and ensuring reliable operation for memory, storage, and peripherals.
Ripple and Noise
Ripple levels stayed well within ATX guidelines, with the +12V rail under 35 mV and the +5V/+3.3V rails below 20 mV at full load. This level of filtering supports consistent power delivery and reduces the risk of instability during intense workloads.
Thermal Performance and Acoustics
The 90 mm hydraulic bearing fan remains off below 20% load, keeping idle noise minimal. During moderate workloads, the fan noise stayed low, around 28 dBA. Under maximum load, cooling was effective, and internal temperatures remained within safe operating limits, demonstrating efficient heat management despite the compact form factor.
Load Testing
The GS 850W handled full system stress testing reliably. During gaming benchmarks, system power draw peaked around 570 W, leaving ample headroom for upgrades or additional components. Voltage and efficiency remained consistent, confirming the unit’s capability to support high-end graphics and CPU combinations.
