iMac 27" 2017 5K retina: does it need an OWC thermal sensor adapter or NOT?

mitridig

macrumors newbie
Original poster
Sep 20, 2011
16
0
Hi,
i managed to change the internal small 32Gb pci-e ssd with a 128Gb Apple pci ssd and swapped the original Apple HDD
with an aftermarket 2Tbyte HDD. I didn't placed an OWC Thermal sensor on the sata cable, even though OWC says it is needed.
I am hearing perfectly the fans NOT blowing at full speed.
What is the truth in the end? Do i need it to install it or not?

Thank u everyone
 

mj_

macrumors 6502a
May 18, 2017
801
468
Austin, TX
I'd be interested in that as well since I am planning to replace my internal HDD with an SSD sometime next year.

Are you getting any temperature readings for the disk drive at all?
 

FrankCataldi14

Suspended
Mar 21, 2020
44
33
I'd be interested in that as well since I am planning to replace my internal HDD with an SSD sometime next year.

Are you getting any temperature readings for the disk drive at all?
Ditto---AppleCare Plus is about to run out on my 2017 and I'm thinking about putting in a bigger SSD and cleaning the fans......
 

tylers67

macrumors newbie
Jul 12, 2015
6
2
Moorpark
I have done this upgrade several times for customers (3rd party sales and repair) and today I had a guy that didn’t want to spend the money for OWC’s thermal sensor

I did the upgrade, installed Mojave, and was ready for the fan to run full speed... nothing!

Checked iStat Menus and it’s reading the sensor fine. I’m going to check in with him tomorrow and see if it ever kicked on.

Maybe Apple added something in a firmware update to fix this but it seems so unlike Apple.
 
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Assim

macrumors newbie
Jun 30, 2020
2
0
I have done this upgrade several times for customers (3rd party sales and repair) and today I had a guy that didn’t want to spend the money for OWC’s thermal sensor

I did the upgrade, installed Mojave, and was ready for the fan to run full speed... nothing!

Checked iStat Menus and it’s reading the sensor fine. I’m going to check in with him tomorrow and see if it ever kicked on.

Maybe Apple added something in a firmware update to fix this but it seems so unlike Apple.
what year was it? I've seen in some places that OS Sierra and more recent will read electronically the temp. can you give us some update, please? thanks
 

tylers67

macrumors newbie
Jul 12, 2015
6
2
Moorpark
what year was it? I've seen in some places that OS Sierra and more recent will read electronically the temp. can you give us some update, please? thanks
As far as I can tell 2012-2017 does not need the OWC in-line thermal sensor anymore. Just as a precaution I did make sure it had the Mojave boot ROM e.g “87.0.0.0.0”
 
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Agilato

macrumors newbie
Jun 5, 2020
12
1
I experimented with different HDD/SSD on my 2015 iMac and for some reason fan behaves differently with different drivers.

I have tried:
- 2.5 Kingston 240GB SSD, fan is in stock 1200rpm
- 2.5 HDD WD Scorpio Black, fan is in stock 1200rpm
- 3.5 WD Black, fan is spins 1800rpm
- 3.5 Seagate Barracuda ST31000524AS, fan is on Full Tootle. 2700rpm

Also i noticed that when u startup the system it process drive about 3-4 mins before ramp up the speed.
If you will run Diagnostics next reboot fan is behaves normally but second reboot ramp up again.
 
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