Microsoft aware of severe throttling issue affecting Surface Pro 6 and Surface Book 2 that leaves devices locked at just 400 MHz

CPU throttling issues aren’t new but it doesn’t make them any less annoying when trouble strikes. As noted in a Reddit thread, Microsoft Surface Pro 6 and Surface Book 2 users are extremely frustrated with their devices experiencing the problem. It is similar to an issue plaguing Surface Pro devices, including this new generation, that Notebookcheck identified back in October; however, if anything, it seems to be getting worse. According to user reports, the Kaby Lake-R-based Intel CPUs in both devices are throttling down to as low as 400 MHz and locking at this frequency.

Users have tracked the problem down to a Windows alert used by components peripheral to the CPU called BD PROCHOT that results in the CPU throttling down to protect it and any other internal components from overheating and suffering damage as a result. Some have been able to workaround the issue by removing their devices from docks or connected AC adapters. Others haven’t, however, had any luck even when rebooting their Surface.

In a message sent to TechRepublic about the matter, Microsoft said “We are aware of some customers reporting a scenario with their Surface Books were CPU speeds are slowed [and] are quickly working to address via a firmware update.” At this stage, however, there is no firm time frame on when the patch will arrive leaving users with devices that are performing well below specification. While some throttling can be expected in thermally constrained devices such as these, the speeds being logged are well below anything that could be described as normal.