Throttled so hard it's almost dead

The yellow boxes in ThrottleStop indicate records of previous throttling events and why. The three yellow BD PROCHOT boxes show that this method of CPU throttling has been used on your CPU since you booted up. Boxes in red mean that this method of CPU throttling is currently active. Your CPU is throttling to 800 MHz because the CPU is receiving a signal on its BD PROCHOT line.

BD PROCHOT stands for bi-directional processor hot. A sensor, likely on your motherboard, has gone bad and it is sending a signal to your CPU which forces it to run as slow as possible because the CPU believes that it is too hot. Your CPU temperatures are fine but your CPU has to obey this request.

When you clear the BD PROCHOT box in ThrottleStop, this is the equivalent of disconnecting the BD PROCHOT signal line that goes to your CPU. As soon as you do this, your CPU will start running at its full rated speed. No more throttling. That is exactly what your pictures show. The 36 multiplier is the normal multiplier that a 4670K uses when 4 cores are active or when you have disabled your C States in the bios.

The C0 state is the state that a CPU is in when it is actively working on a task. When your computer is idle, it will not have to spend much time in the C0 state. It will mostly just be sitting their in C1, waiting for something to do. A fast CPU can process all of the various Windows background tasks a lot quicker than a CPU that is stuck at 800 MHz. When your CPU is running fast, it does not need to spend nearly as much time in the C0 state working. That is why the C0% reported in ThrottleStop decreases. When your CPU is in slow and sluggish mode, running at 800 MHz, it will have to spend far more time in the C0 state processing background tasks. The difference in C0% you are seeing confirms that the CPU at 3600 MHz is running 4.5 times faster compared to 800 MHz. 6.6% / 4.5 = 1.5% Make sense?

This is an obscure but common problem in laptops. The only way to repair this problem is to replace the motherboard. It is far cheaper and easier to just use ThrottleStop and keep the BD PROCHOT signal path permanently disabled.

As mentioned before, disabling BD PROCHOT will not interfere with your CPU throttling if it needs to if it ever gets too hot. The PROCHOT signal (processor hot) is completely different than the BD PROCHOT signal. PROCHOT is internal to the processor. BD PROCHOT is for external sensors.