GAMEMAX GX-850 Pro 850W Gold ATX3.0 PCIe 5.0 Modular PSU
GameMax
GAMEMAX GX-850 Pro 850W Gold ATX3.0 PCIe 5.0 Modular PSU
The GAMEMAX GX-850 Pro 850W Gold ATX3.0 PCIe 5.0 Modular PSU is a fully modular 850W power supply aimed at high-end gaming PC builders and esports system integrators who need reliable, efficient power delivery for demanding GPUs. It pairs an 80 PLUS Gold-certified design with a native PCIe 5.0 12VHPWR connector, making it a straightforward fit for current and next-generation graphics cards without adapters.
Why this product
80 PLUS Gold: over 90% efficiency
The 80 PLUS Gold certification confirms efficiency above 90%, meaning less energy is lost as heat, the fan runs quieter, and overall system temperatures stay lower.
Native PCIe 5.0 12VHPWR connector included
A single 12VHPWR 16-pin connector supports PCIe 5.0 GPUs including RTX 3090 Ti-class cards, delivering up to 600W without requiring an adapter cable.
Fully modular cable management
Every cable is detachable, so only the connections actually needed go into the build — reducing clutter, improving airflow, and making installation tidier.
Silent semi-passive 135mm fan
The 135mm Fluid Dynamic Bearing fan with Axial-Tech design stays off when load is below 20% and operates below 25 dBa, keeping the system near-silent during light use.
Six-point hardware protection suite
OVP, OCP, OPP, SCP, UVP and OTP protections guard connected components against voltage spikes, current surges, short circuits and overheating.
ATX 3.0 standard for modern platforms
Built to the ATX 3.0 specification, it is designed to handle the transient power spikes common with the latest Intel and AMD platforms and discrete GPUs.
- Wattage850W
- Efficiency80 PLUS Gold (90%+)
- ModularityFully Modular
- GPU Connector12VHPWR 16-Pin (PCIe 5.0)
- Fan135mm Fluid Dynamic Bearing
- Noise<25 dBa
- ATX VersionATX 3.0
- Warranty2 Years
- SKUGAM-780
- EAN6931858767521
- Compatible with standard ATX PC cases — dimensions are 150 mm × 86 mm × 160 mm (W × H × D).
- Supports PCIe 5.0 GPUs (including RTX 3090 Ti and newer) via the included 12VHPWR 16-pin connector, up to 600W.
- Works with both modern Intel and AMD platforms requiring ATX 3.0 power delivery.
- Wide input voltage range (110–240 VAC, 50–60 Hz) makes it usable in the UK, EU, US and other regions.
- Available in black or white finish — confirm colour variant at purchase if aesthetics need to match the case.
- Not suitable for SFX or SFX-L form-factor cases — this is a full ATX-size unit.
Best for
- High-end gaming PC builders running PCIe 5.0 GPUs who need a native 12VHPWR connection and headroom up to 850W.
- Quiet-build enthusiasts — the semi-passive fan stays off under light load and remains below 25 dBa under heavier use.
- Cable-management-focused builders who want a fully modular unit so unused cables stay out of the case entirely.
- Efficiency-conscious builders who want 80 PLUS Gold-rated efficiency above 90% to reduce heat and running costs.
- Esports system integrators building reliability-focused rigs who need a full protection suite and a documented MTBF of 100,000 hours.
Trade-offs
- Small form-factor builds — at 150 × 86 × 160 mm this is a standard ATX unit and will not fit SFX or Mini-ITX cases designed for shorter PSUs.
- Very high wattage workstation builds — the 850W ceiling may not be sufficient for multi-GPU or extreme HEDT configurations that demand 1000W or more.
- Buyers needing a long warranty — it comes with a 2-year warranty, which is shorter than the 5- to 10-year coverage offered by some competing units at this power level.
- Non-modular cable purists — while fully modular is an advantage for most builders, those who prefer a single-piece harness for rigidity will find that this design does not support that approach.
Introducing a new series of GameMax power supply the GX-850 Pro available in a black or white edition with 80 PLUS Gold certification brings unbeatable power and a superior performance to your Gaming PC.
The GX-850 Pro partners high-end cooling together with premium components to provide an incredibly silent, top performing product perfect for primary gamers. This intelligent fully modular unit features an instinctive Axial-tech fan design to make cooling more productive and guarantees a flawless performance. On the inside only the best components are used, and a full suite of top tier circuit protections ensures that the power that is delivered to your system is safe and reliable in any environment are used. GameMax have created the ultimate gaming Power supply, the GX-850 Pro is the best choice for high-end gaming PCs and Esports environments.
PCIE 5.0 Ready
The GX-850 Pro includes a 12VHPWR 16-Pin connector offering a powerful and stable performance allowing the PSU to run next-generation GPUs, RTX 3090 TI/PCIE 5.0 GPUs. Max. Power output up to 600W.
Modular Cable Configuration
A Modular cable management design lets you use only the cables you need. Improved airflow and save space and create a cleaner-looking build with the low-profile flat black cables.
Hardware Protection
A full line up top tier circuit protections keeps your build running strong and your hardware safe - OVP (Over Voltage Protection), OCP (Over Current Protection), OPP (Over Power Protection), SCP (Short Circuit Protection), UVP (Under Voltage Protection) & OTP (Over Temperature Protection).
Connectors
20+4 Pin Main Connectors: 1
4+4 Pin 12V Connectors: 2
SATA Connectors: 6
4-Pin Molex Connectors: 3
6+2 Pin PCI-e Connectors: 4
12 Pin PCI-E 5.0: 1
General
| Brand | GAMEMAX |
|---|---|
| Model | GX-850 Pro |
| Form Factor | ATX |
| ATX Version | ATX 3.0 |
| Dimensions (W × H × D) | 150mm × 86mm × 160mm |
| Warranty | 2 Years |
Power & Efficiency
| Total Power Output | 850W |
|---|---|
| 80 Plus Rating | Gold |
| Efficiency | 90% |
| Input Voltage | 110–240 VAC |
| Input Current | 15–8A |
| Input Frequency | 50–60 Hz |
| PFC | Active PFC |
| Operation Temperature | 0–40°C |
| MTBF | 100,000 Hours |
Connectors
| 20+4 Pin Main | 1 |
|---|---|
| 4+4 Pin 12V (EPS) | 2 |
| 12-Pin PCIe 5.0 (12VHPWR) | 1 |
| 6+2 Pin PCIe | 4 |
| SATA | 6 |
| 4-Pin Molex | 3 |
| Modularity | Fully Modular |
Cooling & Protection
| Fan Size | 135mm |
|---|---|
| Fan Type | Fluid Dynamic Bearing, Axial-Tech |
| Fan Control | Semi-passive (starts above 20% load) |
| Noise Level | <25 dBa |
| Protections | OVP, OCP, OPP, SCP, UVP, OTP |
| Safety Certifications | CE, UKCA, FCC, CB, cTUVus, EAC, RoHS, CCC |
Shipping
All our products are shipped from the United Kingdom within 24 to 48 hours of purchase. See our Shipping and Returns page for full details.
Returns
- Tech Syndicate offers a full money-back guarantee on all purchases made in our store. If you are not satisfied with your purchase, we will provide a full refund, no questions asked.
- Refunds are available within 45 days of delivery.
- After the 45-day period you are no longer eligible for a refund, so we encourage you to try the product within the first few weeks to make sure it fits your needs.