ASRock Steel Legend SL-1000P
A compact 1000W Platinum-class ATX 3.1 power supply combining PCIe 5.1 support, native 12V-2x6 GPU power, fully modular cabling, quiet semi-passive cooling and a 10-year warranty.
Quick Product Overview
1000W ATX 3.1 Platform
The Steel Legend SL-1000P provides 1000W of continuous output from a single high-current +12V rail and is designed for modern gaming and workstation systems with demanding CPUs and GPUs.
Native 12V-2x6
PCIe 5.1 support includes a native 600W-rated 12V-2x6 connection. ASRock adds dual-color connector guidance and temperature monitoring to help improve installation awareness and connector protection.
Platinum & Quiet
The SL-1000P carries 80 PLUS Platinum and Cybenetics Platinum efficiency certifications along with Cybenetics Lambda A+ acoustic certification.
Key Specifications
| Exact Product | ASRock Steel Legend SL-1000P |
|---|---|
| Continuous Output | 1000W |
| ATX Standard | ATX 3.1 |
| PCIe Standard | PCIe 5.1 ready |
| Efficiency | 80 PLUS Platinum / Cybenetics Platinum |
| Acoustic Certification | Cybenetics Lambda A+ |
| Cabling | Fully modular |
| +12V Rail | 83.4A / 1000W, single rail |
| Power Excursion | Up to 200% |
| GPU Power | Native 12V-2x6, 600W-rated |
| CPU Power | 2 × EPS connections |
| Traditional PCIe | 3 × GPU power connections |
| SATA | 9 connectors |
| Molex | 3 connectors |
| Cooling | 135mm striped axial fluid-dynamic-bearing fan |
| Semi-Passive Mode | Yes — selectable iCOOL mode |
| Capacitors | 100% Japanese capacitors |
| Dimensions | 150 × 150 × 86mm |
| Warranty | 10 years |
ATX 3.1 & Transient Performance
Modern high-performance graphics cards can create extremely rapid changes in power demand. The ATX 3.1 specification requires compatible power supplies to tolerate these short-duration excursions without allowing the primary output rails to move outside required limits.
Independent testing subjected the SL-1000P to the complete ATX 3.1 transient sequence, including excursions reaching 200 percent of rated output. The PSU successfully passed every ATX 3.1 transient-response test.
Conventional transient testing was less exceptional. The +12V rail performed near the category average, while the 3.3V rail showed a larger voltage drop. All tested rails remained within specification.
12V-2x6 & TempGuard
600W GPU Connection
The native 12V-2x6 connection is rated for up to 600W, supporting compatible modern graphics cards without requiring a multi-connector adapter at the GPU.
Dual-Color Connector
ASRock uses a contrasting green section on the connector to make an incompletely inserted 12V-2x6 plug easier to identify during system assembly.
TempGuard
An NTC temperature sensor at the GPU connector monitors temperature and communicates with the PSU as part of ASRock's cable over-temperature protection system.
Power Connections
The SL-1000P provides two EPS CPU connections, a native high-power 12V-2x6 GPU connection, three traditional PCIe GPU connections, nine SATA connectors and three 4-pin peripheral connectors.
Independent inspection found the cable lengths generally practical, with the 24-pin ATX cable measuring approximately 590mm and the CPU and GPU power cables extending beyond 600mm.
Electrical Performance
Load Regulation
Independent testing found especially tight regulation on the minor rails, while overall voltage behavior remained comfortably inside required limits.
Ripple Suppression
Ripple suppression was a strong area for the SL-1000P, helping maintain clean DC output across changing operating loads.
Transient Response
The PSU passed the full ATX 3.1 transient suite, although conventional +12V transient response was closer to average and 3.3V performance could be improved.
Efficiency
The SL-1000P is certified to both 80 PLUS Platinum and Cybenetics Platinum efficiency standards. Independent testing confirmed that its average efficiency satisfies the Cybenetics Platinum requirements at both 115V and 230V input.
Normal-load efficiency was competitive with comparable 1000W units, while light-load and super-light-load efficiency were particularly strong. That helps reduce unnecessary power loss during everyday desktop use when a high-capacity PSU is operating far below its maximum output.
The standby rail also performed efficiently, while vampire power remained low.
Cooling & Acoustic Performance
Cooling is handled by a 135mm striped axial fluid-dynamic-bearing fan. ASRock's selectable iCOOL mode allows semi-passive operation, keeping the fan stopped during lighter operating conditions.
Independent testing found the passive period unusually long. Under the tested conditions, the PSU could remain effectively silent through a substantial portion of its output range, with fan noise remaining below 20 dBA through much of the higher-load region.
Cybenetics measured average noise at roughly 17 dBA at 115V, supporting the unit's Lambda A+ acoustic certification. Noise increases as the PSU approaches very heavy loads, as expected from a 1000W design.
Internal Platform & Build Quality
The Steel Legend SL-1000P is manufactured for ASRock by HEC. The platform uses a double-sided PCB and a modern high-efficiency power conversion design built around quality components.
Independent teardown analysis identified Infineon primary-side switching components, a Wolfspeed boost diode and Rubycon 105°C-rated primary capacitors. ASRock specifies Japanese capacitors throughout the PSU.
Independent testing also confirmed full rated power delivery under elevated-temperature conditions, demonstrating that the compact 150mm-deep enclosure does not prevent the unit from delivering its rated output.
Protection Features
OCP
Over-current protection.
OVP
Over-voltage protection.
UVP
Under-voltage protection.
OPP
Over-power protection.
OTP
Over-temperature protection.
SCP
Short-circuit protection.
Compact 1000W Design
Despite its 1000W rating, the SL-1000P measures only 150mm deep. That is useful in cases where the PSU compartment must also accommodate drive cages, cable bundles or restricted routing space.
The compact dimensions are paired with a 135mm fan rather than a smaller high-speed cooling solution, helping preserve the low-noise characteristics demonstrated in independent testing.
Works Best With
High-End Gaming PCs
1000W output, ATX 3.1 transient capability and native 12V-2x6 support make the SL-1000P appropriate for properly matched high-performance CPU and GPU combinations.
Performance Workstations
Its 1000W continuous output and strong efficiency provide useful capacity for CPU-intensive and GPU-accelerated workstation systems.
Quiet High-Power Builds
iCOOL semi-passive operation and Lambda A+ acoustics make the PSU particularly interesting for builders who need high output without constant high fan noise.
Owner Satisfaction & What People Are Saying
Positive Factors
- Compact 150mm depth simplifies installation in many cases.
- 1000W capacity provides substantial headroom for performance systems.
- Native 12V-2x6 connectivity eliminates the need for many GPU adapters.
- Dual-color connector design provides a useful visual installation check.
- Semi-passive iCOOL operation keeps light-load noise extremely low.
- Fully modular cabling simplifies routing and unused-cable removal.
- 10-year warranty supports long-term ownership.
Points to Consider
- ASRock is newer to the retail PSU market than several long-established PSU brands.
- Protection thresholds could be tuned more conservatively.
- 3.3V transient behavior was only mediocre in independent testing.
- +12V conventional transient response was closer to average than class-leading.
- 1000W is unnecessary for many mainstream systems.
- Exact Steel Legend model and wattage should be verified before using replacement cables or specifications.
Strengths & Limitations
Strengths
- 1000W continuous output
- ATX 3.1 compliant
- PCIe 5.1 ready
- Passed all ATX 3.1 transient-response tests
- Native 600W 12V-2x6 connection
- TempGuard connector temperature monitoring
- Dual-color 12V-2x6 connector guidance
- 80 PLUS Platinum certified
- Cybenetics Platinum efficiency
- Cybenetics Lambda A+ acoustics
- Strong light-load efficiency
- Good ripple suppression
- Low average noise
- Selectable semi-passive iCOOL mode
- Fully modular cabling
- 135mm FDB fan
- Japanese capacitors
- Compact 150mm depth
- 10-year warranty
Limitations
- Protection thresholds need better tuning
- Minor-rail OCP thresholds are higher than ideal
- 3.3V transient response could be stronger
- +12V conventional transient performance is not class-leading
- Power factor measured lower than some competing designs
- 1000W capacity is excessive for lower-power systems
Who Is It Best For?
The ASRock Steel Legend SL-1000P is aimed at builders assembling powerful gaming PCs and workstations that genuinely benefit from a 1000W PSU and modern high-power GPU connectivity.
Its compact depth also makes it useful when a high-capacity power supply must fit into a chassis with restricted PSU space, while the semi-passive fan system suits users who want low noise during lighter desktop workloads.
Systems with modest CPUs and GPUs generally do not require 1000W. Capacity should always be selected according to the complete hardware configuration rather than assuming that additional wattage is automatically beneficial.
Rockin Box Tech Research Summary
The ASRock Steel Legend SL-1000P combines a modern feature set with solid independent test results. Its 1000W output, ATX 3.1 compliance, PCIe 5.1 support, native 600W 12V-2x6 connection and compact 150mm depth make it well suited to powerful current-generation systems.
Efficiency and acoustics are significant strengths. The PSU satisfies Cybenetics Platinum efficiency requirements, performs particularly well at light loads and carries Lambda A+ acoustic certification. Independent testing also found good ripple suppression and confirmed full rated output under elevated-temperature conditions.
Its strongest modern-platform result is successful completion of the entire ATX 3.1 transient-response test sequence. Conventional transient performance is less exceptional, especially on the 3.3V rail, but remained within specification.
Protection tuning is the primary technical weakness. Independent testing found OCP and OPP thresholds that could be better optimized, including high OCP limits on the minor rails.
Overall, the SL-1000P presents a credible modern 1000W platform with high efficiency, low noise, useful GPU-connector safety features, quality internal components and long warranty coverage.
Research Disclosure
This Rockin Box Tech review is research-driven and based on current ASRock product documentation, independent laboratory testing and publicly available owner/community information.
The product was not necessarily physically tested by Rockin Box Tech. Electrical, efficiency, acoustic and thermal observations are based on published professional testing rather than claims of in-house laboratory testing.
This review applies specifically to the ASRock Steel Legend SL-1000P. Specifications and test results from the 850W or 1200W Steel Legend models should not automatically be applied to this 1000W unit.
Actual PSU noise, temperature, efficiency and suitability vary according to system hardware, load, ambient temperature, chassis airflow and operating conditions.
Power-supply capacity should always be selected for the complete system. Wattage, efficiency certification and brand name alone do not establish PSU quality or suitability.
Manufacturer specifications, internal components, cable configurations, certifications and warranty terms may change after publication.