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macrumors newbie
Original poster
May 17, 2014
Hello all! This is my first post!

I want to upgrade a couple things on my iMac. I have the base model mid 2011 21.5 inch with the 2.5ghz i5. The stock hard drive is a 512gb HD, and I want to upgrade it to a 1TB, and also replace the optical drive with a SDD drive.

I know about the fan issues when replacing the HD but what if I put in a bigger HD that came out of an iMac from the same year? would I still have the same fan issues? Shouldn't that HD have the correct firmware on it?

I've never taken apart an iMac, but I'm a very competent DIY'er


macrumors regular
Aug 2, 2011
I read from OWC that you need to get the same brand of HDD as your original iMac HDD to avoid the fan thermal sensor issue. E.g. WD 512GB to get WD 1TB.
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