I'am new here and want to share a fix I found to fix on one of my MSI R7950 Twin Frozr 3GD5/OC. Problem was that the fan of one of my GPUs was permanently at maximum while the temperature was in an acceptable range (~77°C). Well after hours spent on the web I found out that some MSI R7000 series have a faulty diode that can be removed as shown there:
http://linustechtips.com/main/topic/25436-msi-hd-7950-twin-frozr-fan-issue-and-fix/
https://forum-en.msi.com/index.php?topic=167047.100

Since I removed this diode, the card is a lot less noisy and the fan lifetime will probably be longer as well

hope that can help someone here