Will the Core i5-12600K bottleneck the RTX 5090?

Yes, at 1440p the Core i5-12600K is estimated to limit the RTX 5090 by about 28%. The effect is larger at 1080p and smaller at 4K.

What power supply do I need for a Core i5-12600K and RTX 5090?

Estimated system load is about 825 W. A quality 1200 W unit leaves roughly 30% headroom for transient spikes.

Is this pair better at 1080p or 4K?

1080p: CPU-limited 33% (moderate CPU bottleneck). 1440p: CPU-limited 28% (moderate CPU bottleneck). 4K: CPU-limited 10% (balanced).

PCPairs

Core i5-12600K + RTX 5090: bottleneck check

28%

CPU-limited at 1440p. Moderate CPU bottleneck.

CPU GPU

The Core i5-12600K cannot feed the RTX 5090 fast enough at 1440p, so the card sits partly idle in CPU-heavy games.

By resolution

Resolution	Limiting part	Severity	Verdict
1080p	CPU	33%	moderate CPU bottleneck
1440p	CPU	28%	moderate CPU bottleneck
4K	CPU	10%	balanced

The Core i5-12600K is the limiting part at every resolution, even at 4K (10%). The RTX 5090 is a much stronger card than this processor can drive — plan a CPU upgrade before spending more on graphics.

Specifications

Intel Core i5-12600K
Cores / threads	10 / 16
Max boost	4.9 GHz
Socket	LGA1700
Max turbo power	150 W
Released	2021
Gaming index	72 / 100
Multi-core index	62 / 100

NVIDIA GeForce RTX 5090
VRAM	32 GB
Board power	575 W
Released	2025
1080p index	100.0 / 100
1440p index	100 / 100
4K index	100.0 / 100

Power supply

CPU 150 W + GPU 575 W + about 100 W for motherboard, memory, storage and fans gives an estimated peak load of 825 W. We recommend a 1200 W unit (80 Plus Gold or better) so transient spikes from the graphics card stay inside the PSU's comfort zone. Try other pairs in the PSU calculator.

Best CPU for the RTX 5090 Best GPU for the Core i5-12600K RTX 5090 PSU requirements

Compare nearby pairs

Same CPU, other GPUs

Same GPU, other CPUs

Indexes are relative estimates aggregated from published reviews; real results vary by game, settings, memory speed and drivers. Methodology.