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I want to upgrade the HDD in my iMac Intel 21.5" mid 2010 ( EMC 2389 , core i3 3.06 GHz, original HDD 500GB SATA/16MB cache , WD5000AAKS). I would appreciate it if anyone could tell me whether HDD with SATA III 6.0Gb/s (for example, WD Desktop Mainstream WDBH2D0010HNC-NRSN 1TB 7200 RPM 64MB Cache SATA 6.0Gb/s 3.5") is compatible and I can install it on my iMac. Also I need to know if the on-board thermal sensor interface can be used the same way as it was originally. Thanks in advance
Here’s the IFIXIT guide to install a replacement drive: iMac Intel 21.5" EMC 2389 Hard Drive Replacement Your systems SATA port is only SATA II (3.0 Gb/s) So sadly you can’t use most of the Western Digital drives as they are FIXED SATA III (6.0 Gb/s) drives as WD no longer makes SATA II drives. So what to do?? Well you can still use an AUTO SATA port sense drive! These drives have the ability to match to the systems SATA port speed. As an example the Seagate FireCuda drives. Here you can see the SATA Transfer Rates Supported (Gb/s) line lists all three SATA speeds! 6.0/3.0/1.5. Unlike a standard HD the FireCuda is a SSHD so you gain some zip over a standard HD! OK so we’ve found a workable drive now we still have the onboard SMC thermal sensor to deal with. Apple leveraged a diagnostic sensor the manufactures had on the drives accessing it though the AUX header. As Apple sourced drives from a few different vendors (3) they ended up having different sensor cables as the different makers used different pins (no standard). Todays drives are different so one can’t depend on the cable to even work with the same drive maker anyways so we need to find a better approach. As it turns out OWC has the answer here! OWC In-line Digital Thermal Sensor for iMac 2009-2010 Hard Drive Upgrade which allows us to bypass the onboard sensor to an externally mounted unit which works across any drive you might use. So the bottom line here is: You’ll need the Seagate drive (Auto SATA port sense) & OWC in-line thermal sensor!
While this is a couple years old, it’s still relevant. I have a spare Patriot Blast 240gig SATA III SSD drive, that originally was going into an old Core2Duo MacBook Pro a couple years ago. I got it all setup, probably with a slower external adapter, but then it would panic on boot once installed. The speed was overwhelming the MBP, so maybe 10-30 seconds into the boot, it would die. When searching, it turns out it was just much too much, and with SSD drive only lists SATA III. Now a couple years later, I’m upgrading an old 24” iMac of the same era. I am used to there being backward compatibility, but Dan points out that that’s not here unless specified. And a WD HD that has auto sense was then used by Raven. Without auto sense, or something in between to slow things down, SATA III is too much for a pre-SATA III system. It’s like drinking from a straw, vs pouring the whole gatorade cooler over your head. Too bad. For mine, I’ll have to use it in an external device that can slow it down, or wait to put it into a machine that can handle it. Thanks for the info!!!
