HomeGPU ComparisonsNVIDIA GeForce RTX 4080 vs NVIDIA GeForce RTX 3090
Power Supply Comparison

NVIDIA GeForce RTX 4080 vs NVIDIA GeForce RTX 3090

Transient-aware PSU requirements, ATX compliance, cable safety audit, and power efficiency comparison.

SpecificationNVIDIA GeForce RTX 4080NVIDIA GeForce RTX 3090
Performance TierUltraUltra
Total Board Power (TBP)320W350W
Transient Peak (modeled)461W631W
Minimum Recommended PSU650W1000W
PCIe Connector Required12v-2x68pin-x3
Number of Connectors13
ATX 3.1 Required✓ Yes✗ No
Daisy-Chain Safe✗ No✗ No
MSRP$1199$1499
GenerationAda LovelaceAmpere

PSU Requirement Breakdown

NVIDIA

NVIDIA GeForce RTX 4080

Sustained Draw371W
Transient Peak461W
Min PSU Required650W
Cable Safety⚠ Warning

⚠ NVIDIA GeForce RTX 4080 requires an ATX 3.1 PSU with a native 12V-2x6 cable. DO NOT use adapter cables from older 8-pin connectors. If your PSU lacks a native 12V-2x6 port, you must upgrade your PSU.

NVIDIA

NVIDIA GeForce RTX 3090

Sustained Draw431W
Transient Peak631W
Min PSU Required1000W
Cable Safety⚠ Warning

⚠ NVIDIA GeForce RTX 3090 requires 3 separate 8-pin PCIe power cables. DO NOT daisy-chain — each cable must run directly from the PSU to the GPU.

Power Efficiency Verdict

NVIDIA GeForce RTX 4080 requires less PSU headroom per dollar spent. It needs 650W recommended at $1199, versus 1000W at $1499 for the NVIDIA GeForce RTX 3090.

Note: NVIDIA GeForce RTX 4080 requires an ATX 3.1 PSU with a native 12V-2x6 cable — factor in a possible PSU upgrade cost if you currently own an ATX 2.x unit.

Frequently Asked Questions

Which PSU do I need for NVIDIA GeForce RTX 4080?

NVIDIA GeForce RTX 4080 has a 320W TBP but can spike to 461W during transient loads. We recommend a minimum 650W ATX 3.1 PSU with a native 12V-2x6 connector for safe operation with headroom.

Which PSU do I need for NVIDIA GeForce RTX 3090?

NVIDIA GeForce RTX 3090 has a 350W TBP and transient peak up to 631W. We recommend a minimum 1000W ATX 3.1 PSU for stable operation.

Does NVIDIA GeForce RTX 4080 or NVIDIA GeForce RTX 3090 need ATX 3.1?

NVIDIA GeForce RTX 4080 requires an ATX 3.1 PSU with a native 12V-2x6 connector. Do not use adapter cables. NVIDIA GeForce RTX 3090 uses 8pin-x3 and does not require ATX 3.1.

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