Chosen Solution

hi everyone! I’m using an Intel based iMac (Mid-2011 model) 21.5 inch. It comes with a 500GB hard drive (ST3500418AS) and I’d like to replace (not add a new drive by removing the optical disk drive) that drive with an SSD (Samsung 840 EVO-Series 1TB 2.5-Inch SATA III Model #MZ-7TE1T0BW) SSD link below: http://amzn.to/1Ea56Ok the ssd itself is 2.5 inch and I’m going to convert that drive to 3.5 inch drive by using a WD icepack which is sold on amazon.com for about $20 usd WD Icepack link below: http://amzn.to/1rITB9O first I’m going to attach the ssd into the WD icepack and then I’m planning to replace the original HDD that comes with the iMac by installing the SSD. My questions are:

  1. does apple allow 3rd party SSD’s for iMac?
  2. do I need any additional cable kit?
  3. is it enough to change just the drives? (I mean HDD comes with a termal sensor, does the SSD need a termal sensor?)
  4. do I need any software after installing the SSD (if possible) to control iMac’s fan speed [I heard some people complaining about their fan speeds and the loudness of the fans]

First you have a spare SATA port in this model so you don’t need to remove your current HD or the optical drive. So you can follow this IFIXIT guide: Installing iMac Intel 21.5" EMC 2428 Dual Hard Drive Kit. Go to Step 46 as you can see you are wedging the second drive (HD or SSD) behind the optical drive. Once you’ve put the SSD in you can then create a Fusion drive across both your HD and SSD gaining the benefits of each. If you decide to just replace your HD for a SSD thats fine to. But you’ll need to use this special cable: OWC In-line Digital Thermal Sensor for iMac 2011 Hard Drive Upgrade. Frankly, I think the best option here is swapping out your HD for a SSHD (hybrid HD). Here you’ll gain the performance of the SSD but the storage capacity of a HD. Here’s the Seagate web site: Seagate Desktop SSHD and here is the spec sheet for the SSHD series: Desktop SSHD specsheet.

Given that this thread dates from the 2014/2017 timeframe, I think the SSHD recommendation no longer applies. I put in a Seagate SSHD back then and have been thoroughly unimpressed with its performance from day one. Prices of SSDs have plummeted since then which makes SSHDs no longer viable.

Hi, i have same issue, Beware iMac 27 mid 2011, don’t work with samsung 860 EVO (Because samsung use unsupported new controller) also same situation can be with 850 EVO (i didn’t check with this series), so optimal for upgrade without any risk will be use 840 EVO series. Symptomatic is next: When you connect 860 EVO (I check it) or 850 EVO (I didn’t check it 850 EVO, so info for 850 EVO maybe not correct). You can start from internet recovery but you cannot do fusion drive, for fusion drive you should start from USB recovery, yes you can do fusion drive with 860 EVO or 850 EVO but then when will be recovery from time machine you will se error and time machine is stop, then if you will try install new system to you new fusion formatted disk, you will cannot install, not sierra, not sierra high, maybe el captain will work but you will see many error when install it (6 hours maybe), if you still install some OS don’t start to be happy, because will be many errors and white screen. So by the way. If you try to instal os to pure ssd, it’s also will be with error. So conclusion don’t use 860 EVO and 850 EVO with iMac 27 mid 2011 (I have core i5 3,1). So your SSD will work with USB 2.0 on your iMac, or need to buy thunderbolt ssd adapter or thunderbolt usb 3.0

If you install a 3rd party SSD you will need to download software to enable the TRIM support. I have been using this program for the last couple of years Trim Enabler. Otherwise totally go with the recommendations in the previous answer. Personally I am more partial to SSD’s especially since the prices have only been falling. I highly recommend the Samsung 840 or 850 Pro drives. Dual HD upgrade is the way to go!

I installed a 1 TB hybrid drive in my 2009 27" iMac, the reason I did this was so I could remove the sensor off the old 1 TB drive and put it on the new hybrid drive (SSHD). That way the temp sensor does not run the fans at super full speed. Also at the time I read about SSD’s they need to be purged once in a while, maybe not now but 3 years ago I think that was the case. So with the hybrid drive as it needs to it can purge the caching flash part of the drive. In the end the programs and files I use all the time are right there and the stuff I don’t use all the time is still in the deeper storage on the HD side, so it starts up quick and programs I use all the time open right up. This seems to work well for me. I have a 2 TB drive on the time machine that I only turn on once in a while.

Hi @danj , I went to a PC repair store and they told me that I do NOT need any thermal sensor cable to replace the original HDD with an SSD, because the SSD doesn’t have the pins to connect it.

  1. Do you confirm that I need a thermal sensor cable to swap my original HDD with an SSD?
  2. Where do I connect the thermal sensor cable if the SSD doesn’t have the right pins? Thanks!

Hello, I’m a bit lost: will the cable sold by iFixit be ok with the thermal control? Or should I go for the one sold by OWC? Is there any specific feature I should look for on the SSD itself before purchasing? I’m really interested in changing my drive, but don’t want at all the software solution to control the fans (program crashes: no control, what about Bootcamp, etc.) thanks a lot! Pierre

Why replace the existing HD with a SSD, when it is possible to install the SSD and keep the original HD? I did it on my iMac, SSD is now my startup disk for both MacOS and Windows using BootCamp. Only question: How does the TRIM work for partitioned drives? Do I have to enable it on Mac & PC, or just Mac? Thanks!

I was thinking about updated my mid 2011 iMac hard drive to SSHD. I was looking at the Seagate 1TB Gaming SSHD SATA 32GB NAND SATA 6Gb/s 2.5-Inch Internal Bare Drive (ST1000LX001). I liked this, because it features a 32GB SSD vs the 8GB in the desktop version. I know I’ll need to buy a mounting kit with it since it is a laptop hard drive, but will I need to worry about the thermal control issue? Thanks.

I was thinking about updated my mid 2011 iMac hard drive to SSHD. Will I need any special cable as well as mounting kit? Reiko

Hello Dan, Just so i understand your amazingly thorough post, if I don’t want to use the HD drive in my mid 2011 21.5 iMac, do I just follow the instruction provided, adding the SDD drive using the optical thermal sensor from OWC?? My confusion is that your link shows you how to add an SSD drive to make a dual drive with the HD, but when you mention the option of not using the original HD, you use the word “replace” and then mention the use of the OWC optical thermal sensor. Am I removing the old HD and replacing it with the new SSD or am I adding the new SSD keeping the old HD,but using just the SSD? hope that makes sense. thanks in advance.

Hello! I am hanging on for the next desktop release due late 2017 (arrgh) meanwhile I have a slow mid 2011 27 - inch imac. Will installing a SSHD speed it up or should I just say goodbye and rent a machine while I wait? Halp.

Wondering if this WD drive will work to swap without any additional cables etc.. https://www.wdc.com/products/internal-st…

I’m sorry as I realize this is an older thread. So I failed to do my due dilligence prior to buying a new SSD for my wife’s Mid 2011, 21.5 iMac. I wanted to know if this is possible. I want to install the SSD in the spare bay behind the optical drive. prior to doing that was thinking I would clone the HDD to the SSD, then wipe the HDD. This way the iMac runs the OS from the SSD and has another storage drive. it is Mid 2011 model so I do not have much faith the HDD has much life left in her so want to transfer the OS and other valuables off of it. Figure I will use it for nonessential things. I have a 2 TB Lacie external HDD that I would place anything super important onto. Does this plan sound too difficult or is it possible?