Fan at full speed after adding SSD

[decksnap]

I just completed an install of a 1tb SSD into my 2011 iMac 27". This is the method where you mount it behind the optical drive and keep the existing HDD. After I put it all back together and booted up, the fan in the bottom right corner of the machine is running permanently at full speed.

Using Macs Fan Control, I can see that the system is getting actual sensor values for all items, including optical drive, hdd, gpu, etc. So I feel like it can't be an errant sensor? However, the 'ODD' (disk drive fan) is shown to be running at full speed.

Anybody have any thoughts? This is a tough one to google because for those who replaced the HDD, there are obvious known sensor/fan issues. There shouldn't be in this case.

 

[nambuccaheadsau]

Go to macsales and get the heat sensor kit. They need replacing when you replace the drive. From the 2009 replacing the hard drive with anything but the original brand and model causes this fan increase period. The 2012 21.5" iMac introduced the slow 5400rpm laptop style drive to overcome this problem.

81ºF is about 28ºC and that is just fine for winter. Down Under mid summer and 30ºC today and my Blade Drive shows 45ºC. As much as I like Mac Fan Control the proper way is the best way.


https://eshop.macsales.com/item/OWC/DIDIMACHDD11/ 45ºC, still within normal range.

 

[decksnap]

Thanks for the reply... this is for a drive addition not a drive replacement. New heat sensor should not be necessary.

Ironically I ordered that kit first, tore down my entire Mac, then realized I had the wrong kit. Had to go without a machine for a while.

 

[nambuccaheadsau]

Are okay.

Be aware however the hard drive is SATAIII (6gb/ps) and the optical drive is only half that at SATA II (3Gb/ps) and if you used a Samsung SSD it has been reported they do not play nice at times with backwards compatibility. Heat should not be a problem.


https://www.quora.com/Are-all-SATA-3-drives-SATA-2-compatible

 

[decksnap]

The ssd is mounted behind the optical drive. It uses an empty Sata slot, not sure if it’s 2 or 3 but either way it’s 10x faster than using my hdd!

 

[arkieboy72472]

The ssd is mounted behind the optical drive. It uses an empty Sata slot, not sure if it’s 2 or 3 but either way it’s 10x faster than using my hdd!

I did the exact same thing. At first, I had my SSD in a bracket in the HDD spot, but later i tossed in a 2TB Hard drive and them put the ssd behind the optical drive. I had the fan issue bit because neither my hard drive nor my ssd has a sensor. Now that I think of it, maybe I need a sensor kit for mine also.

Anyhow, I just used the same program and compared my results to yours. Mine runs a bit cooler but I am unsure why.

 

[BugeyeSTI]

I just completed an install of a 1tb SSD into my 2011 iMac 27". This is the method where you mount it behind the optical drive and keep the existing HDD. After I put it all back together and booted up, the fan in the bottom right corner of the machine is running permanently at full speed.

Using Macs Fan Control, I can see that the system is getting actual sensor values for all items, including optical drive, hdd, gpu, etc. So I feel like it can't be an errant sensor? However, the 'ODD' (disk drive fan) is shown to be running at full speed.

Anybody have any thoughts? This is a tough one to google because for those who replaced the HDD, there are obvious known sensor/fan issues. There shouldn't be in this case.

I added a Samsung SSD using the extra sata port while keeping the HDD with the factory temp sensor like you did and my fans work normally. I use the SSD as the main boot drive and the HDD as extra storage.. Maybe a connection isn’t seated completely or possibly the harness you used to connect the two drives may be bad. You may need to open it up and check everything you did during installation..

 

[decksnap]

Thank you. I’m hoping to narrow down what connector could be causing this because I’ve already opened it back up and checked all the connects once. They all seem right. Argh

 

[GoodWheaties]

Hmmm I would also be suspicious of loose connections but if that is already checked then who knows. An alternative would just using something like Temperature Gauge Pro to force the fans to a certain speed but you will need to set up rules so it won’t overheat then when it actually needs to go higher.

On a different topic, an alternate mounting place for the SSD is directly on top of the HDD. When I had my 2011 I found that a 7mm SSD fit perfectly there behind the screen so as not to block airflow to the GPU cooler. Easier access too if you ever want to pull it out. But my GPU failed later multiple times anyway.