ASRock Steel Legend SL-850P 850W Platinum Modular PSU
ASRock
ASRock Steel Legend SL-850P 850W Platinum Modular PSU
The ASRock Steel Legend SL-850P 850W Platinum Modular PSU is designed for enthusiast PC builders who need a high-efficiency, fully modular power supply that can support modern graphics cards and next-generation ATX standards. It solves the problem of noisy, inefficient power delivery by combining 80 PLUS Platinum and Cybenetics Platinum certification with an intelligent fan control mode that keeps the unit silent under light to moderate loads.
Why this product
80 PLUS Platinum and Cybenetics Platinum certified
It carries both 80 PLUS Platinum and Cybenetics Platinum efficiency ratings, along with LAMBDA A+ acoustic certification, meaning it wastes less power as heat and runs quieter than units at lower efficiency tiers.
ATX 3.1 and PCIe 5.1 ready with native 12V-2x6
It ships with a native 12V-2x6 connector built to the PCIe 5.1 specification, so no adapter is needed for current high-end graphics cards.
iCOOL fan mode keeps it silent at low loads
A physical switch lets you choose between semi-passive mode — fan off at low to medium loads — and continuous fan operation for sustained heavy workloads.
TempGuard monitors VGA connector temperature
An NTC sensor at the VGA connector tracks temperature in real time and signals the unit to respond before heat becomes a problem.
100% Japanese capacitors rated to 105 °C
Every capacitor inside is Japanese-made and rated to 105 °C, contributing to the long service life that backs the 10-year warranty.
Fully modular cabling keeps builds tidy
All cables detach completely, so unused connectors stay out of the case and airflow is unobstructed.
- Rated Power850 W
- Efficiency80 PLUS Platinum / Cybenetics Platinum
- Form FactorATX 3.1
- Fan135 mm Striped Axial FDB
- ModularFully Modular
- Warranty10 Years
- MTBF100,000 hours @ 25 °C
- Dimensions (L × W × H)150 mm × 150 mm × 86 mm
- SKUASR-3355
- EAN4711581492646
- Fits standard ATX cases — 150 mm × 150 mm × 86 mm footprint.
- Compatible with ATX 3.1 motherboards and ATX 2.x boards via the 24-pin motherboard connector.
- Supplies up to two EPS 12V CPU connectors (one 4+4-pin and one 8-pin), covering dual-CPU and high-end single-CPU boards.
- Ready for PCIe 5.1 graphics cards via the native 12V-2x6 (12+4-pin) connector with TempGuard.
- Accepts universal AC input (100–240 V, 50–60 Hz), making it suitable for use in most regions worldwide.
- Cybenetics LAMBDA A+ acoustic certification is marked with an asterisk in the product listing — verify the final rating on Cybenetics' published database if acoustic compliance is critical.
Best for
- High-end single-GPU desktop builds — 850 W of continuous output with a native 12V-2x6 connector covers current enthusiast graphics cards without adapters.
- Noise-sensitive workstations — iCOOL semi-passive mode and Cybenetics LAMBDA A+ acoustic certification suit users who prioritise quiet operation during everyday tasks.
- Long-term ownership — a 10-year warranty and 100,000-hour MTBF rating at 25 °C make it suitable for builders who do not want to replace their PSU mid-system-lifecycle.
- Builders who value clean cable management — full modularity means only the cables you actually use go into the case.
- Internationally mobile users — universal 100–240 V input means the unit works across different mains voltages without a separate converter.
Trade-offs
- Dual high-end GPU workstations — 850 W continuous output and a single 12V-2x6 connector limit multi-GPU configurations that each demand their own high-current connector.
- Builds requiring more than nine SATA devices — the connector set tops out at nine SATA 5-pin connectors, which may not cover high-density storage systems.
- Extremely compact ITX chassis — at 150 mm depth it is a standard ATX length and will not fit cases that require SFX or SFX-L units.
- Users who need only passive cooling at all times — iCOOL mode off runs the 135 mm fan continuously, and iCOOL mode on still activates the fan under higher loads.
The Steel Legend series power supply unit offers options of 1200W, 1000W, 850W. Certified for 80 PLUS Platinum efficiency and Cybenetics Platinum rating, along with LAMBDA A acoustic certification, it ensures outstanding energy performance.
With ASRock Classic Green connectors, users can easily see if the connector has been plugged properly. The NTC sensor at the VGA connector monitors the temperature and sends signal the PSU to ensure safe operation.
●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 |
|---|---|
| Form Factor | ATX 3.1 |
| Total Power | 850 W |
| Warranty | 10 Years |
| MTBF | 100,000 hours @ 25 °C |
| Dimensions (L × W × H) | 150 mm × 150 mm × 86 mm |
Efficiency & Cooling
| 80 PLUS Rating | Platinum |
|---|---|
| Cybenetics Efficiency | Platinum |
| Cybenetics Acoustic | LAMBDA A+ |
| Fan | 135 mm Striped Axial FDB |
| Fan Control | iCOOL Intelligent Mode (Switch) |
| Total Power Excursion | 200% |
Power Output
| Continuous 12V Output | 70.9 A |
|---|---|
| AC Input | 100–240 V~, 50–60 Hz, 10–5 A |
| Protections | OCP, SCP, OVP, UVP, OTP, OPP |
| 5V BOOST | Yes (Built-in) |
| PCIe 5.1 TempGuard | Yes |
| Capacitors | 100% Japanese, 105 °C rated |
Connectors
| Motherboard (24-pin) | 1 |
|---|---|
| EPS 12V CPU (4+4-pin) | 1 |
| EPS 12V CPU (8-pin) | 1 |
| PCIe 5.1 (12+4-pin) Dual Color | 1 |
| PCIe (6+2-pin) | 2 |
| PCIe (8-pin) | 1 |
| 4-pin Peripheral | 3 |
| SATA 5-pin | 9 |
| Cable Type | 12+4-pin: Sleeved — Others: Individual Braided Pattern |
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.