My Zephyrus Duo 4090 with an R9 7945XHX and 4090 Laptop GPU is having a strange problem with CPU throttling. After playing some games or doing benchmarks such as 3DMark Time Spy, my CPU clock and voltage throttles down to a fraction of when I start playing. The throttle only goes away when I reboot. Here is how simple it is to reproduce the throttling:
Freshly rebooted, start Time Spy and do a normal run. My score is normal. My CPU and GPU temperatures never go above 85C, so I ruled out thermal throttling.
Now my CPU is throttled. The max core clock is now at around 3500 Mhz out of the expected 4800 - 5200 Mhz. And the max voltage is 0.7V out of the expected 1.2V.
Running Time Spy again will give me a greatly reduced score. My CPU score has dropped from 14K expected to around 10.5K. Cinebench shows me a similar drop in performance. From my expected 35K to around 22K.
My Google-fu has not helped me with this and I tried everything I could think of. Windows power options, UXTU, ASUS Armory Crate options, nothing has helped. The only way to get rid of the throttle is to reboot and it just starts all over again. What could be the cause of this?