Asus VivoBook 15 with Ryzen 3500U Clock speed locks to 400 Mhz
OS Name : Microsoft Windows 10 Home Single Language
Version : 10.0.19043 Build 19043
System Model : VivoBook_ASUSLaptop X512DA_X512DA
Processor : AMD Ryzen 5 3500U with Radeon Vega Mobile Gfx, 2100 Mhz, 4 Core(s), 8 Logical Processor(s)
BIOS Version/Date : American Megatrends Inc. X512DA.316, 02-02-2021
My 1.2 Year old laptop (not under warranty) with Ryzen 3500U randomly locks into a clock speed of400 Mhz within minutes after turning it on even at lite loads. Hardware info shows HTC and PROCHOT_EXT has been triggered but the temperatures aren't abnormal. Cooling system is working perfectly, I myself cleaned the fan and has been providing with proper ventilation during operation. Once throttling starts the device never exit that state unless the device is made to shut down. Can't even work with MS Office properly during throttling. Also the device stops charging once it starts throttling
TROUBLESHOOTING DONE BY MYSELF :
1) Cleaned CPU fan and provided proper ventilation using a laptop stand
2) Made sure that all available temperatures are under the limit
3) Windows, Drivers and BIOS are up to date
4) Tried to operate the device solely on battery and on charger (by physically disconnecting the battery from device), throttling happened in both cases
5) Installed Ubuntu and checked, Same thing happens in that case also
Another person with same device and same issue as reported on AMD community that he has reapplied thermal compound and reinstalled the Operating system from a service center and the issue hasn't been resolved.
I'm Having logs from Hwinfo and Speccy but can't post links here.