For an NVIDIA reference-design RTX 4090, the stated required system power is 850 W, but that is not a guarantee for every build: NVIDIA bases it on a system with a Ryzen 9 5900X and says a higher rating may be needed depending on configuration. A 1000 W unit is a documented higher-capacity option, but the right choice depends on your exact graphics card, processor, cabling and case. Three current manufacturer-documented candidates are the CORSAIR RM1000x SHIFT, MSI MEG Ai1000P PCIE5 and be quiet! DARK POWER 13 1000 W.
How much power does an RTX 4090 need?
NVIDIA lists 450 W total graphics power for its reference RTX 4090 and 850 W required system power. The 850 W figure is for an entire PC configured with a Ryzen 9 5900X; it is not the graphics card’s own draw or a universal recommendation for every system. NVIDIA cautions that “A higher power rating may be required depending on your system configuration.” CPU choice, overclocking and other components affect the margin your build needs. NVIDIA’s RTX 4090 specifications and system-preparation guidance also note that add-in-board card specifications can differ from the reference design.
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Use the recommendation for your exact card model as the starting point, then account for the rest of the PC. If the card maker specifies a higher PSU capacity or different connectors, follow that model-specific guidance rather than assuming the reference figure covers it.
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These are manufacturer-documented candidates, not a performance ranking. The specifications below come from product pages, not from a common independent test of noise, electrical regulation, reliability or transient response.
#1 Best Overall
| Model | Manufacturer-listed output | GPU connection and standard | Efficiency rating | Important fit or purchase check |
|---|---|---|---|---|
| CORSAIR RM1000x SHIFT | 1000 W continuous | ATX 3.1; included PCIe 5.1 12V-2×6 cable | 80 PLUS Gold, as named on the product page | Side-mounted modular connections need clearance and cable access; cited page is a white NA-market SKU. Check regional model and included cables. 10-year warranty listed by CORSAIR. CORSAIR product specifications |
| MSI MEG Ai1000P PCIE5 | 1000 W | ATX 3.1 and PCIe 5.1 ready; native 600 W 16-pin connector; eight PCIe 6+2-pin connectors | 80 PLUS Platinum | Fully modular. Confirm regional SKU and bundled cable details. MSI specifications |
| be quiet! DARK POWER 13 1000 W | 1000 W | ATX 3.1; native 12V-2×6 and PCIe 6+2-pin connections | 80 PLUS Titanium | The listed specifications establish connectors and efficiency certification, not comparative noise or electrical performance. be quiet! product specifications |
Choose based on the details that matter to your build
- CORSAIR RM1000x SHIFT: Consider it if you want a documented 12V-2×6 lead and its side-facing modular ports suit your case layout. Measure clearance for both the PSU and the cables before buying.
- MSI MEG Ai1000P PCIE5: Its listed eight PCIe 6+2-pin connectors provide a useful specification to compare against your card’s requirements. Verify which cables come with your exact regional unit.
- be quiet! DARK POWER 13 1000 W: Its manufacturer lists ATX 3.1, native 12V-2×6 and Titanium efficiency. Those facts alone do not establish that it is quieter or performs better than the other candidates.
Prices, retailer stock and comparable independent test results are not established here, so compare current local listings and independent testing before treating any model as the best value or best-performing choice.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Do you need ATX 3.1 or a native 12V-2×6 cable?
A modern PSU with a native GPU power cable can avoid relying on the adapter included with a graphics card, but the connector must match the card and PSU instructions. NVIDIA describes powering its reference RTX 4090 with either three PCIe 8-pin cables through the included adapter or one 450 W-or-greater PCIe Gen 5 cable. Its setup guidance also mentions support for three or four PCIe 8-pin cables and advises checking the PSU vendor’s instructions. The exact add-in-board card may have different requirements. Check NVIDIA’s system-preparation guidance and your card manufacturer’s instructions for your model.
Rank #2
- 80 PLUS GOLD CERTIFIED: Provides up to 92% high efficiency, reducing energy consumption and heat while ensuring stable power delivery for high-end systems.
- Fully Modular Design: The psu features fully modular soft dragon-pattern cables to minimize cable clutter, improve airflow, and enhance cooling efficiency for a cleaner, neater PC build.
- ATX 3.1 & PCIe 5.1 Ready: Compliant with ATX 3.1 and PCIe 5.1, supports up to 2x total power excursion and 3x GPU power excursion for stable high-performance power supply. Comes with a dual-color dragon-pattern 16-pin PCIe 5.1 cable with orange connector for easy and secure plug-in confirmation.
- 140MM FDB Fan with Smart Control: Larger 140mm fan design ensures quieter operation and superior heat dissipation. Smart fan control auto-sleeps at low load for silent usage and adjusts speed dynamically under high load for efficient cooling performance.
- Premium Components & Stable Design: Features 100% Japanese 105°C-rated capacitors for exceptional durability and stability. Paired with DC-DC & half-bridge resonant design to deliver higher efficiency, lower heat, quieter operation, and ultra-reliable power output.
ATX 3.1 and PCIe 5.1 labels are useful specification cues, but do not substitute for checking the supplied cable and its rating. Never assume a modular cable is compatible merely because it fits the PSU. Use only cables approved for the exact PSU model, and if using the GPU’s adapter, follow both GPU and PSU manufacturers’ cable instructions and use the required number of separate PCIe leads.
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Rank #4
- Fully Modular PSU: Reliable and efficient, low-noise power supply with fully modular cabling, so you only have to connect the cables your system build needs.
- Intel ATX 3.1 Certified: Compliant with the ATX 3.1 power standard, supporting PCIe 5.1 platform withstands 2x transient power excursions from the GPU.
- Keeps Quiet: A 120mm rifle bearing fan with a specially calculated fan curve keeps fan noise down, even when operating at full load.
- 105°C-Rated Capacitors: Delivers steady, reliable power and dependable electrical performance.
- Modern Standby Compatible: Extremely fast wake-from-sleep times and better low-load efficiency.
Rank #3
- ATX 3.1 & PCIe 5.1 Certified: Future-proof your build. Fully compliant with Intel ATX 3.1 and PCIe 5.1 for seamless compatibility with NVIDIA RTX 40/50 Series GPUs. Includes a native 12V-2x6 cable delivering up to 600W of direct power-eliminating melting adapters and safely handling 200%+ transient power spikes
- Ultra-Quiet 148mm Fan: Enjoy LAMBDA A++ certified silent performance, measured at just 13.42dB average at 750W load. Featuring one of the largest fans in standard ATX PSUs, it spins at significantly lower RPMs, delivering superior cooling efficiency and near-silent operation even under full gaming loads.
- Cybenetics Gold Dual-Certification: Cooler, quieter, and more efficient. Achieves an elite 87%+ efficiency rating via advanced LLC resonant topology. Unlike basic 80 PLUS tests, this rigorous dual-certification guarantees superior power efficiency AND acoustics, reducing heat and extending system lifespan
- 100% Japanese Capacitors with 10-Year Warranty: Built to outlast the competition. Engineered with premium 105C Japanese electrolytic capacitors for rock-solid stability under sustained loads. Backed by our hassle-free 10-year warranty and responsive support
- Fully Modular With Premium Flat Cables: Build like a pro, look like a pro. All cables are detachable-use only what you need for a cleaner interior, improved airflow, and easier installation especially in compact cases. Features premium flexible flat cables in stealth black that route effortlessly through tight spaces and behind motherboard trays for custom builders who demand both performance and aesthetics
Compatibility checklist before you buy
- Identify the exact graphics card. Read its maker’s PSU recommendation and connector requirements; an add-in-board RTX 4090 can differ from NVIDIA’s reference design.
- Estimate whole-system demand. Consider the CPU, overclocking, drives, pumps and other components rather than sizing for the GPU alone.
- Verify the cable plan. Confirm the PSU includes a cable compatible with the card, or follow the card’s adapter instructions. Use only cables approved for your PSU model.
- Check physical clearance. Compare PSU dimensions with the case’s PSU compartment and allow room to route and connect cables. Pay special attention to side-mounted ports on the RM1000x SHIFT.
- Confirm the exact regional SKU. Check the included cables, warranty terms, price, stock and return policy with the retailer in your region; product-page details can vary by market.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
