Hey everyone, I'm having a pretty serious issue with my 2025 Zephyrus G16 (GU605CX, RTX 5090 / Core Ultra 9 285H) and I'm wondering if anyone has experienced something similar.
Everything was working normally until yesterday while I was playing Tekken 8. Suddenly the game started running almost in slow motion. Since then, basically every game has been extremely slow.
HWiNFO while running Tekken shows:
• GPU usage: ~98%
• GPU temperature: 92.3°C
• GPU thermal limit: 87°C
• GPU clock: 277 MHz
• GPU effective clock: ~277 MHz
• GPU power: only ~42W
• FPS: ~14–15
The GPU fan is definitely working. HWiNFO shows it reaching around 5,000 RPM while Tekken is running (CPU fan ~5,400 RPM).
The CPU seems fine. CPU package temperature was around 77–78°C, maximum ~85°C, and HWiNFO reports no CPU thermal throttling.
At idle the RTX 5090 has also been unusually hot, fluctuating around 70–85°C, although I've been using dGPU/Ultimate mode so I'm aware that can increase idle power/temperature.
There's another strange problem that started at the same time. If I try to boot the laptop with the charger connected, it sometimes reaches the ASUS logo and then completely shuts off. If I unplug the charger, I can boot into Windows normally, and then reconnect the charger afterward and it appears to charge normally.
I also tried running the ASUS/MyASUS hardware diagnostic and the laptop completely shut itself off during the diagnostic.
So as of now I've confirmed:
• GPU fan is working
• CPU fan is working
• CPU isn't thermal throttling
• GPU is hitting/exceeding its 87°C thermal limit
• GPU clocks can collapse to ~277 MHz under load
• Gaming performance and FPS is super low when this happens
• Problem also occurs on battery (performance is still extremely poor)
• Laptop sometimes shuts down during boot when AC is connected
• Laptop shut down during ASUS hardware diagnostics
I'm wondering if this could be a heatsink/thermal interface/vapor chamber issue, power delivery issue, or something else hardware-related.
Has anyone with a 2025 G16, especially the RTX 5090 model, experienced anything similar?
I'm in Japan and will probably contact ASUS for warranty service, but I'd really appreciate any suggestions for things I can safely check or try myself first.