Latest Microsoft update slows some Surface devices to 400MHz

Some Microsoft Surface Pro 6 and Surface Book 2 devices are throttling down to crippling low speeds of 400MHz, post the new firmware update that was rolled out on August 1.

The throttle-lock appears to be caused by an Intel CPU flag called BD PROCHOT (bi-directional processor hot), which can be set by any peripheral, telling the processor to throttle down to decrease system temperature, a report in the Tech Republic said on Thursday.

The issues were flagged by several users on Reddit. 

However, along with the CPU issues, Microsoft`s latest firmware updates have been causing Wi-Fi issues for several users.

Surface Book and Surface Pro 6 owners have complained on Microsoft`s support forums that the latest Marvel Wi-Fi driver, supplied with Microsoft`s Surface firmware updates on August 1, is not allowing devices to connect to some 5GHz wireless networks. 

We experienced these issues on a Surface Pro 6 device, and the problems could be related to certain router combinations, the TechCrunch reported.

"If you have Wi-Fi issues on a Surface device since the updates earlier this month, you can simply roll back the driver in device manager, which will restore access to 5GHz networks. A Microsoft volunteer moderator claims the company is `working on an update`," the TechCrunch report added.