ThrottleStop / bd-prochot

BD PROCHOT

BD PROCHOT is bidirectional processor hot. PROCHOT is the CPU's own emergency brake at the thermal spec (often 100°C). BD PROCHOT lets another part of the board - usually the GPU or a VRM sensor - pull that same brake even when the CPU package is sitting at 60°C.

ThrottleStop next to GPU-Z showing GPU at 83 C while CPU is monitored — GPU-Z at 83°C GPU temperature while ThrottleStop watches the CPU. Shared heat pipes are why BD PROCHOT exists on gaming laptops.

When people clear the box

A lot of 2016-2019 notebooks throttle the CPU because a cheap GPU thermal target (sometimes 68-73°C) asserts BD PROCHOT. Clocks fall off a cliff, Limit Reasons may not even look "thermal" on the CPU side. Clearing BD PROCHOT in ThrottleStop is the classic fix. It is also the setting that can let a dying fan cook the GPU while the CPU happily stays at 4 GHz.

Only clear BD PROCHOT if you can see GPU temperature (GPU-Z or the NVIDIA/AMD box in Options) and you understand the cooler. ThrottleStop 9.7 now locks BD PROCHOT when it is disabled so a sleep/resume cycle does not restore OEM behaviour without you noticing.

ThrottleStop Limit Reasons and GPU-Z during a heat-soaked load — If the GPU is already at 81°C and Limit Reasons is red, clearing BD PROCHOT does not add cooling. Fix paste, a stand, fan control, or a ThrottleStop undervolt first.

PROCHOT Offset on the Options window (and per profile in 9.7) moves the CPU's own thermal throttle point. Asus sometimes ships an offset of 8, so a 100°C chip starts thermal throttling at 92°C. Lowering offset toward 0 recovers spec, if the field is not locked.