Reddit has a lot of reports from users who are saying that after they had installed the latest Crimson driver, the fan remained locked at 20%. This is usually happening without the knowledge of the user, who finds out when the system crashes. If they’re lucky, the system will reboot, but that's not always the case. It’s possible for GPU to die in the process, and that makes things a lot more complicated.AMD acknowledged the issue and promised a fix will be released later today. The bug is reportedly limited to select GPUs but until the fix is out we recommend being very careful if you're using the new AMD GPU drivers.
We are aware of low fan speed reports on select GPUs with Radeon Software Crimson Edition. We intend to publish a hotfix on Monday.— AMD Radeon Graphics (@AMDRadeon) November 29, 2015