Question: Disk usage causes high CPU temperature and Wifi issues
Whenever my Mac does some moderately heavy writing to the disk, the system becomes very unstable and unresponsive and the Wifi connection drops permanently. In addition, the CPU temperature rises above 100°C without the fan speed increasing at all. At the same time, the activityMonitor app does not show an extremely high CPU usage, as I would have expected, with this high temperature. This whole behaviour can be triggered by something as simple as a software update.
In contrast to that, if I just start a process that does heavy computing, without writing to the disk, the CPU temperature also rises very high but the fan speed also increases, the system stays usable and responsive and the Wifi stays connected. This is why I assume that it must have something to do with the disk writing. It also reliably happens when using the BlackMagic Disk Speed Tool (which eventually will freeze the whole system).
I already tried to reset the SMC, but that did not solve the problem. So far I have not found anything online about this issue. Is this likely to be a failure of my hard drive (SSD)? Did anyone experienced this problem as well?
MacBook Pro with Retina display, macOS Sierra (10.12.6)