NVIDIA's latest flagship GPU is 3.0 GHz, MSI's Kombustor GPU stress tool used. The RTX 4090 can run at very high clocks with NVIDIA's new Ada Lovelace architecture. NVIDIA has shown already the card can run at 2.85 GHz with factory settings.

Gamers and overclockers can reach 3.0 GHz with Kombustor. The RTX 4090 can operate at 3.0 GHz / 615.8W or at defaults 425.6W / 2.64 GHz, according to Bilibili screenshots. 

The Leaker reported only GPU temperature and memory hot spots were missing. GeForce RTX 4090 has a 450W TDP. Most custom models are similar. Most cards have "OC" or "Gaming" modes with TDPs above 500W. Founder Edition GPUs have a power limit of 600W, which may explain why this test used a 600W card.

GeForce RTX 4090 running at 3.0 GHz and 616 Watt running GPU stress tool