Best PSU for Core i9-14900KS & RTX 5090
This ultra-high-end build delivers peak 4K ray-traced gaming performance and excels in demanding professional rendering or AI workloads.
1200W
850W
71%
Enthusiast
🏆 Recommended Power Supplies
Hand-picked for your 1200W target — sorted by overall value.
Corsair RM1200x Shift Fully Modular ATX Power Supply – Side Interface – ATX 3.1 & PCIe 5.1 Compliant – Zero RPM Fan Mode – 105u00b0C-Rated Capacitors – 80 Plus Gold Efficiency – Black
Side-interface design simplifies cable routing in compatible wide-chassis cases.
Efficiency80+ Gold
FormATX
CablesFull-Modular
Price$194.99
ASUS TUF Gaming 1200W Gold (1200 Watt, ATX 3.0 Compatible Fully Modular Power Supply, 80+ Gold Certified, Military-Grade Components, Dual Ball Bearing, Axial-tech Fan, PCB Coating, 10 Year Warranty)
Robust military-grade build quality provides long-term stability for high-wattage draws.
Efficiency80+ Gold
FormATX
CablesFull-Modular
Price$204.99
be quiet! Pure Power 12 M 1200W Modular Power Supply | 80 Plusu00ae Gold | ATX 3.1 | PCIe 5.0 GPUs and 6+2 pin connectors | 12VHPWR Cable Included | Silent 120mm be quiet! Fan – BN513 I 10 Year Warranty
ATX 3.1 compliance ensures modern safety standards and quiet operation under load.
Efficiency80+ Gold
FormATX
CablesFull-Modular
Price$179.90
CORSAIR HX1500i (2025) Fully Modular Ultra-Low Noise ATX Power Supply with 12V-2×6 Cable u2013 ATX 3.1 & PCIe 5.1 Compliant, Cybenetics Platinum Efficiency, Fluid Dynamic Bearing Fan u2013 Black
Want extra headroom for future GPU upgrades or overclocking? This 1500W unit gives you peace of mind.
Efficiency80+ Gold
FormATX
CablesFull-Modular
Price$349.99
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📊 Quick Comparison
See the key differences at a glance.
| # | Model | Wattage | Efficiency | Modular | Price |
|---|---|---|---|---|---|
| 1 | Corsair RM1200x Shift Fully Modular ATX Power Supply – Side Interface – ATX 3.1 & PCIe 5.1 Compliant – Zero RPM Fan Mode – 105u00b0C-Rated Capacitors – 80 Plus Gold Efficiency – Black | 1200W | 80+ Gold | Full-Modular | $194.99 |
| 2 | ASUS TUF Gaming 1200W Gold (1200 Watt, ATX 3.0 Compatible Fully Modular Power Supply, 80+ Gold Certified, Military-Grade Components, Dual Ball Bearing, Axial-tech Fan, PCB Coating, 10 Year Warranty) | 1200W | 80+ Gold | Full-Modular | $204.99 |
| 3 | be quiet! Pure Power 12 M 1200W Modular Power Supply | 80 Plusu00ae Gold | ATX 3.1 | PCIe 5.0 GPUs and 6+2 pin connectors | 12VHPWR Cable Included | Silent 120mm be quiet! Fan – BN513 I 10 Year Warranty | 1200W | 80+ Gold | Full-Modular | $179.90 |
| ⬆️ | CORSAIR HX1500i (2025) Fully Modular Ultra-Low Noise ATX Power Supply with 12V-2×6 Cable u2013 ATX 3.1 & PCIe 5.1 Compliant, Cybenetics Platinum Efficiency, Fluid Dynamic Bearing Fan u2013 Black Upgrade | 1500W | 80+ Gold | Full-Modular | $349.99 |
🔌 Power Budget
Your system uses 71% of the recommended PSU output — well within the efficient operating range.
1200W (Recommended)
System draw: 850W
Headroom: 350W (30%)
💡 Why 1200W?
Power Calculation
CPU + GPU draw, plus ~100W for motherboard, RAM, fans, and storage.
30% Headroom
Extra capacity absorbs transient power spikes, keeps efficiency in the sweet spot, and leaves room for future upgrades.
80 Plus Efficiency
We only recommend certified PSUs. Higher ratings mean less wasted energy, lower heat, and quieter fans.
🌿 Power Efficiency Tips
Use native 12VHPWR cables to ensure stable power delivery to the 5090.
Maintain aggressive fan curves to dissipate high thermal output from components.
🎯 What This Build Can Do
Gaming
Suitable for modern games with good performance based on your system configuration.
Productivity
Great for office work, multitasking, and everyday computing tasks.
Content Creation
Can handle basic video editing and content creation workflows.
🔧 Installation Guide
Quick Checklist
- Mount the PSU with its fan aligned to your case airflow.
- Only connect cables you actually need (modular PSUs).
- Use dedicated PCIe power cables for NVIDIA GeForce RTX 5090 — no daisy-chaining.
- Boot-test with side panel open before final assembly.
⚠️ Special Note
Check case clearance for side-mounted cables if choosing the Corsair Shift model.
🔗 Explore More Builds
See PSU recommendations for other CPU + GPU combinations.