Best 1000W SFX PSUs for Tiny Rigs and ATX 3.1 Setups
The 1000W SFX power supplies (PSUs) deliver full-size power in compact form factors, ideal for high-end small form factor (SFF) builds and ATX 3.1-compatible systems. This guide highlights top options featuring modular cabling, PCIe 5.1 readiness, and efficient cooling. Each model below is evaluated for noise, cable flexibility, and compatibility with modern GPUs. Explore five reliable choices to power demanding GPUs in compact cases without sacrificing airflow or ease of installation.
| Product | Brand | Form Factor / Watts | Key Feature |
|---|---|---|---|
| Lian Li SP Platinum 1000W SP1000P.B | Lian Li | SFX 1000W | Fanless mode at low load; flexible cables; SFX-to-ATX bracket |
| CORSAIR SF1000 (2025) | Corsair | SFX 1000W | Platinum efficiency; ATX 3.1; PCIe 5.1; fully modular |
| Lian Li SP Platinum 1000W SP1000P.W | Lian Li | SFX 1000W | Fanless at low load; flexible cables; SFX-to-ATX bracket |
| Thermaltake Toughpower SFX 1000W | Thermaltake | SFX 1000W | 80+ Platinum; PCIe 5.1; ATX 3.1 compatibility; modular |
| ASUS ROG Loki SFX-L 1000W | ASUS | SFX-L 1000W | ROG heatsinks; 120mm PWM ARGB fan; ATX 3.0 compatibility |
Lian Li SP Platinum 1000W SP1000P.B
The SP1000P.B from Lian Li is a premium SFX power supply rated at 1000W, supporting ATX 3.1 and PCIe 5.1. It includes a fanless mode that activates at ≤40% load to minimize noise, while the fan engages only when needed. Flexible DC cables simplify routing in tight builds and improve airflow. The included SFX-to-ATX bracket increases compatibility with larger cases that can still benefit from compact PSUs.
CORSAIR SF1000 (2025)
The CORSAIR SF1000 (2025) brings Platinum-level efficiency to a compact SFX power supply. It is ATX 3.1 compliant and PCIe 5.1 ready, designed to handle transient spikes and power-hungry PCIe 5.1 GPUs. Fully modular with Type-5 Micro-Fit connectors, it maximizes cable management in tight cases while maintaining solid power delivery for high-end builds in small footprints.
Lian Li SP Platinum 1000W SP1000P.W
This white variant mirrors the SP1000P.B with identical performance characteristics. It emphasizes silent operation via a smart cooling design that enables fanless mode at light loads, flexible cables for cleaner builds, and the SFX-to-ATX bracket for broader compatibility across case styles. Ideal for aesthetics-conscious builds where white hardware complements the overall theme.
Thermaltake Toughpower SFX 1000W
The Toughpower SFX 1000W from Thermaltake is an 80+ Platinum-certified unit designed for maximum efficiency in compact builds. It supports PCIe Gen 5.1 readiness and ATX 3.1 standards. Its fully modular, low-profile cables help create clean cable management in tight SFF cases while delivering reliable power for power-hungry GPUs and CPUs alike.
ASUS ROG Loki SFX-L 1000W
The ASUS ROG Loki SFX-L 1000W features ROG heatsinks over critical components for lower temps and longer life. Its axial-tech 120mm PWM fan helps maintain quiet operation, and the ATX 3.0 compatibility ensures readiness for PCIe Gen 5 GPUs. This model blends performance with a distinctive cooling design suitable for enthusiasts prioritizing thermal headroom and reliability.
Buying Guide: Key Purchase Considerations
- Form factor and space: SFX vs. SFX-L shapes affect case compatibility. Ensure your chassis has adequate clearance for the PSU height and the length of cables in modular designs.
- Power and headroom: 1000W capacity is beneficial for future GPU upgrades or power-hungry CPUs; assess your current and planned components to avoid oversizing beyond needs.
- ATX 3.1 and PCIe 5.1 readiness: These standards support higher efficiency and improved transient handling for next-gen GPUs and CPUs. Check for native 12V-2×6 PCIe connectors for stable GPU power delivery.
- Efficiency and noise: Look for 80 Plus Platinum or Gold ratings and cooling designs (fanless at low load or PWM-controlled fans) to balance heat and acoustic performance.
- Modularity and cable management: Fully modular systems simplify routing in tight builds. Flexible/detachable cables can improve airflow and aesthetics in compact cases.
- Durability and warranty: A long warranty (often 7–10 years) signals confidence in reliability. Consider electrolyte capacitor ratings and component quality when comparing models.
- Brand ecosystem and support: Reputable brands offer better RMA support and spare part availability, plus compatibility with future motherboard and GPU standards.
- Cooling strategy: Some units use fanless idle modes or larger fans for better thermal balance. Assess willingness to trade light noise for extended lifespan and stability under load.