Surface PCs hit with issue throttling CPUs down to 400MHz

Surface Pro 6 with Aqua keyboard
Surface Pro 6 with Aqua keyboard (Image credit: Daniel Rubino / Windows Central)

What you need to know

  • Recent firmware updates appear to have caused an issue that aggressively throttles the CPU on some Surface devices.
  • Both the Surface Pro 6 and Surface Book 2 seem to be affected, with CPU speeds throttled down to 400MHz.
  • Microsoft has acknowledged the issue and is working on a fix.

Microsoft's Surface Pro 6 and Surface Book 2 devices are suffering from a CPU throttling issue. According to user reports on Reddit, CPU speeds are being randomly throttled down to 400MHz.

"We are aware of some customers reporting a scenario with their Surface Books where CPU speeds are slowed," a Microsoft spokesperson said to TechRepublic in a statement. "We are quickly working to address via a firmware update."

What's causing the issue isn't apparent, but TechRepublic reports that it may have something to do with an Intel CPU flag called BD PROCHOT, which can be used to tell the system to throttle down when components become too hot. This flag is used on non-Surface devices as well, so it's presumed — but not certain — that recent firmware updates have introduced the issue to Surface Pro 6 and Surface Book 2 devices.

This throttling issue comes not long after Surface devices were reported to have an issue with connecting to 5GHz Wi-Fi networks following a driver update. Thankfully, there is a workaround for that issue. However, for CPU throttling problems, we'll have to wait to hear more from Microsoft on any potential fixes.

Dan Thorp-Lancaster

Dan Thorp-Lancaster is the former Editor-in-Chief of Windows Central. He began working with Windows Central, Android Central, and iMore as a news writer in 2014 and is obsessed with tech of all sorts. You can follow Dan on Twitter @DthorpL and Instagram @heyitsdtl