Will the Ryzen 9 5900X bottleneck the GTX 1660 Super?

No. At 1440p the GTX 1660 Super is the limiting part, which is the normal state for a gaming PC. The Ryzen 9 5900X has headroom to spare. This is a model estimate from performance indexes, not a measured FPS loss.

What power supply do I need for a Ryzen 9 5900X and GTX 1660 Super?

Sustained gaming load is about 307 W using the GTX 1660 Super's measured draw. A 450 W unit is the safe choice.

Is this pair better at 1080p or 4K?

1080p: GPU-limited 19% (balanced). 1440p: GPU-limited 27% (GPU-bound (normal)). 4K: GPU-limited 44% (CPU overkill).

PCPairs

Ryzen 9 5900X + GTX 1660 Super: bottleneck check

27%

GPU-limited at 1440p. GPU-bound (normal).

CPU GPU

The GTX 1660 Super is the part working hardest at 1440p, which is what you want. The Ryzen 9 5900X keeps about 27% in reserve.

By resolution

Resolution	Limiting part	Severity	Verdict
1080p	GPU	19%	balanced
1440p	GPU	27%	GPU-bound (normal)
4K	GPU	44%	CPU overkill

The GTX 1660 Super is the limit at every resolution and by a wide margin at 4K (44%). The Ryzen 9 5900X is overkill for this card: a faster GPU would give you far more frames than any CPU change.

Specifications

AMD Ryzen 9 5900X
Cores / threads	12 / 24
Max boost	4.8 GHz
Socket	AM4
TDP	105 W manufacturer-published TDP — sustained turbo can be higher · AMD
Released	2020
Gaming index	67 / 100
Multi-core index	74 / 100

NVIDIA GeForce GTX 1660 Super
VRAM	6 GB
Board power	125 W
Released	2019
1080p index	19.9 / 100
1440p index	15 / 100
4K index	11.3 / 100

Power supply

The GTX 1660 Super measured 127 W average while gaming (140 W highest 20 ms spike, TechPowerUp). With the Ryzen 9 5900X at its TDP of 105 W and about 75 W for the rest of the system, the sustained load is about 307 W. A 450 W unit is the safe choice. Details on the GTX 1660 Super PSU page or try other pairs in the PSU calculator.

Upgrade paths

CPUs that remove the bottleneck

AM4

Cards that use the Ryzen 9 5900X fully

Best CPU for the GTX 1660 Super Best GPU for the Ryzen 9 5900X GTX 1660 Super PSU requirements

Same CPU, other cards

All

Same card, other CPUs

All

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