ASRock Steel Legend SL-850G 850W 80 Plus Gold Modular PSU
ASRock
ASRock Steel Legend SL-850G 850W 80 Plus Gold Modular PSU
The ASRock Steel Legend SL-850G 850W 80 Plus Gold Modular PSU is a fully modular power supply built for mainstream desktop system builders who want efficient, quiet and long-lasting performance. It delivers 850W with 80 PLUS Gold and Cybenetics Platinum efficiency ratings, native 12V-2x6 GPU connectivity for PCIe 5.1 cards, and a 10-year warranty that removes the usual concern about long-term reliability.
Why this product
80 PLUS Gold and Cybenetics Platinum efficiency
It carries both 80 PLUS Gold and the stricter Cybenetics Platinum efficiency rating, meaning less energy is lost as heat and your electricity bill stays lower under typical loads.
Ultra-quiet: under 20 dB on average
The Cybenetics LAMBDA A+ acoustic certification reflects real-world noise below 20 dB on average, making it one of the quieter options in its class.
iCool fan stays off at low to medium loads
In iCool Mode, the 135mm FDB fan remains completely off until load or temperature rises, giving silent operation during everyday tasks.
Fully modular with native 12V-2x6 connector
Only the cables you need go in, keeping airflow clear. The included native 12V-2x6 connector supports the latest PCIe 5.1 GPUs without an adapter.
100% Japanese capacitors rated to 105°C
Every capacitor is Japanese-made and rated to 105°C, contributing to longevity even in warm chassis environments.
10-year warranty
ASRock backs this unit with a 10-year warranty, one of the longest available in the consumer PSU market.
- Power Output850W
- Efficiency80 PLUS Gold / Cybenetics Platinum
- ModularFully Modular
- Noise LevelLess than 20 dB (average)
- Native GPU Connector12V-2x6 (PCIe 5.1)
- Fan135mm Striped Axial FDB
- Warranty10 Years
- Dimensions150mm × 150mm × 86mm (L × W × H)
- SKUASR-779
- EAN4710483949081
- Fits standard ATX cases — dimensions are 150mm (L) × 150mm (W) × 86mm (H).
- Meets ATX 3.1 and PCIe 5.1 standards, compatible with the latest motherboards and GPUs.
- Includes a native 16-pin 12VHPWR (12V-2x6) connector for current high-end PCIe 5.1 graphics cards.
- Includes CPU power cables for both 4+4-pin (2× 8-pin) motherboard connectors.
- Cybenetics certification badge may not appear on earlier packaging units; the official Cybenetics website has the latest certification status.
- Not suitable for SFX or TFX small-form-factor cases — this is a full ATX-size unit.
Best for
- Mainstream and high-end PC builders who want Gold-or-better efficiency without paying for a boutique brand.
- Quiet-first builds — the sub-20 dB average and zero-RPM iCool mode suit home offices and media systems where noise matters.
- PCIe 5.1 GPU owners who need a native 12V-2x6 connector and want to avoid third-party adapters.
- Long-term system keepers who value the 10-year warranty and 105°C-rated Japanese capacitors for extended service life.
- Cable-management-conscious builders who benefit from a fully modular design that keeps unused cables out of the case.
Trade-offs
- Small-form-factor builds — at 150mm × 150mm × 86mm it is a standard ATX unit and will not fit SFX enclosures.
- Non-modular cable preferences — there are no fixed cables; users who prefer a semi-modular unit to avoid losing cables will need to look elsewhere.
- Workstation or server loads above 850W — the rated output is 850W; builds requiring 1000W or more should consider higher-wattage options in the Steel Legend range.
- Continuous-fan cooling preference — iCool Mode ON (default) keeps the fan off under light loads; users who prefer the fan always spinning must switch to iCool Mode OFF.
The Steel Legend series power supply unit offers options of 1200W, 1000W, 850W, 750W, and 650W, available in "Steel Black" and "Steel White" ideal for mainstream systems. Certified for 80 PLUS Gold efficiency and Cybenetics Platinum rating, along with LAMBDA A+/A acoustic certification, it ensures outstanding energy performance. The Cybenetics certification on the packaging has been updated. Some earlier units may not show the badge. For the latest certification details, please visit the official Cybenetics website. Product specifications and performance remain unchanged.
The Steel Legend series power operates at less than 20 dB of noise on average, earning the prestigious Cybenetics Lambda A+ certification. This recognition underscores the Steel Legend series' outstanding noise control performance, making it an exceptional choice for users seeking ultra-quiet operation.
With ASRock Classic Green connectors, users can easily see if the connector has been plugged properly.
- iCOOL Mode ON: The power supply runs more efficiently. The fan stays off during low to medium loads, reducing noise and improving energy efficiency. The fan only activates when the load or temperature increases.
- iCOOL Mode OFF: The fan runs continuously, regardless of load. This may increase noise slightly but provides consistent cooling and better performance under heavy loads.
The fluid seal design and the herringbone structure provides an extremely long lifespan and noise minimization. 105 °C Japanese-made Capacitor and Solid Capacitor, makes prolonged life span possible. Full suite of protections to keep all components safe during normal to extreme power levels. ASRock offers an outstanding 10 –Year warranty, guaranteeing long term reliable and peace of mind operation.
General
| Brand | ASRock |
|---|---|
| Model | SL-850G |
| Color | Steel Black |
| Form Factor | ATX |
| ATX Standard | ATX3.1 & PCIe5.1 Ready |
| Warranty | 10 Years |
Power & Efficiency
| Power Output | 850W |
|---|---|
| Efficiency Certification | 80 PLUS Gold |
| Cybenetics Certification | Cybenetics Platinum and Lambda A+ |
| +12V Rail | 70.9A |
| Built-in Feature | 5V BOOST function |
Cooling & Acoustics
| Fan Size & Type | 135mm Striped Axial FDB Fan |
|---|---|
| Fan Control | iCool Intelligent Fan Control (semi-passive) |
| Noise Level | Less than 20 dB (average) |
| Capacitors | 100% Japanese-made, 105°C rated |
Cables & Connectors
| Modular Design | Fully Modular |
|---|---|
| Native GPU Connector | 12V-2x6 (PCIe 5.1) |
| Motherboard | 24-pin ATX |
| CPU Power | 2× 8-pin |
| PCIe Connectors | 3× 6+2-pin |
| SATA Connectors | 3× SATA |
| Molex Connectors | 1× Molex |
| Dimensions | 150mm × 150mm × 86mm (L × W × H) |
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.