My Dell laptop is experiencing the old problem of the power adapter failing to be recognized by the computer. I know for a fact it is just a break in the data cable in the line, because if I position it just right, the cable is recognized and the computer stops throttling the CPU to 20%. Is there any way that this can be disabled, so that I don't have the fiddle with my power cord every time I plug the computer in?
Dell CPU Throttling – How to Stop Throttling with Power Adapter
cpudell-inspironlaptoppower supplythrottling
Best Answer
I've done some investigation into this and found that there's probably no good way to prevent recent Dell laptops from throttling the CPU when it doesn't detect an OEM AC adapter (or one with a broken data pin.)
Disabling SpeedStep or "additional sleep modes" or messing with the power profiles in the BIOS makes no difference. The "Intel Extreme Tuning" utility doesn't seem to support these motherboards as all overclocking options are locked out, but when a non-OEM charger is connected up it reports that CPU thermal throttling is engaged, and CPU-Z shows the FSB multiplier down to 5x and the core voltage at 0.6 volts.
My guess is that perhaps the BIOS is designed to send false motherboard temperature readings to the CPU when a non-OEM adapter is detected, causing it to throttle. It seems Dell was very serious about locking you in to OEM adapters when they designed this system.
Edit: I found a utility that will allow you to disable the unknown adapter throttling, under Windows at least (I don't know yet if the utility will work under Linux, or if there is something similar.) ThrottleStop has a checkbox called "BD PROCHOT" which causes the CPU core voltage and multiplier to reset to normal when disabled. Apparently this is a "2 way signal path to the CPU. It allows other components in a laptop like the motherboard or GPU to send a signal to the CPU which tricks the CPU into thinking it is too hot", confirming that the way this "feature" is implemented by the BIOS is through sending this signal to the CPU when an unknown AC adapter is detected.