I have recently replaced my SATA drive on my iMac 27" late 2012. It is a WD 4 TB (red) and it seems to have the expected temp sensor. The fan is running on 1600 - 1700 rpm even when everything is cold while expecting 1200 rpm (see attached file). This gives a noise I didn't had before. "iStat menu" observes a reasonable temperature on the disk so it should have a temp sensor. Any ideas what the reason might be?
