If you click on Limts and open up Limit Reasons, when your CPU is stuck at 800 MHz, Limit Reasons will likely show you BD PROCHOT lit up in red. We know that is the reason for throttling. What I am saying is that without proper documentation from your motherboard manufacturer, there is no way to find out exactly what sensor is feeding a signal to your CPU along the BD PROCHOT line and forcing it to throttle.
To troubleshoot you need to replace parts. First the motherboard and if that does not solve the problem then the CPU. If it is the motherboard and you get this problem solved today, it could happen again a week or a month or two from now. Some MSI boards are really bad for this problem because they have a LN2 / Slow Mode switch on the motherboard that fail long before they should.
Last edited by unclewebb; 07-22-2019 at 07:57 AM.