Skip to main content

Send us a Topic or Tip

Have a suggestion for the blog? Perhaps a topic you'd like us to write about? If so, we'd love to hear from you! Fancy yourself a writer and have a tech tip, handy computer trick, or "how to" to share? Let us know what you'd like to contribute!

Thanks for reaching out!

Five Things You Need to Know Before Upgrading Your 2009 or Later iMac

PR_imac_HDDkitWant to upgrade your 2009 or later iMac’s hard drive or memory? There’s a very good chance that it can be done, depending on the model you own. But before you dive in on your upgrade – and even if you already have begun – there are some very important things you need to know.

The Rocket Yard has outlined a guide on some of the most crucial information you’ll need when it comes to upgrading your iMac.

1) Avoid the Noise
If you have previously researched a guide on how to upgrade the hard drive in your iMac, you might have come across fellow iMac owners commenting on issues involving a blaring, revving or noisy fan.

If you haven’t, we will break it down for you:

The problem: With the introduction of the iMac, Apple’s factory-installed drives contained custom firmware that communicated thermal data to the System Management Controller (SMC). Unfortunately, off-the-shelf hard drives don’t include the custom firmware, and as a result, the SMC is unable to monitor the temperature of the hard drive. This causes the iMac fans to run at full speed and fail Apple diagnostics as a failsafe. Despite various “hacks”, the best solution was to still use Apple’s SMC to ensure proper monitoring of drive and system health.

The solution: Fortunately, OWC was able to come up with a solution with its In-Line Digital Thermal Sensor – the first hardware digital thermal sensor on the market allowing a third-party SATA drive to be installed in an iMac. The sensor eliminates “blaring” fan noise and maintains proper system fan control through the iMac’s System Management Controller. The sensor is designed specifically for the iMac, requires no software hacks, and ensures compatibility with Apple’s built-in diagnostic processes.

So, if you’ve upgraded your iMac’s hard drive and notice a blaring fan, don’t panic. There is a solution. For more on this topic, please read this Rocket Yard article.

2) Maximum Internal Capacity
It might not seem so on the surface, but the all-in-one iMac can fit more storage internally than you might have thought*. In fact, some iMac models have more than one drive bay and can even swap out the optical drive for Data Doubler. With our My Upgrades tool, you can see how much storage each iMac model from 2009-current is compatible with.

Professional Installation

3) Professional Installation Recommended
While the sleek design makes late 2012-current iMac models aesthetically pleasing, it also brings challenges when upgrading internal hardware. If you are planning an upgrade for one of these iMacs, it is highly recommended that you seek professional installation. After all, an iMac is much less aesthetically pleasing with a crack on its screen.

4) Adding More Memory
Lots of OWC RAMEvery iMac – aside from some of the latest 21.5” models – is compatible with a memory upgrade. In fact, the 27-inch Late 2015 iMac with Retina 5K display is compatible with up to 64GB of RAM!

Visit our convenient My Upgrades tool to see how much memory your iMac is compatible with.

5) Newly Vintage, But Sierra Compatible
Apple considers iMacs models from before 2009 “obsolete”. The models from 2009 are considered “vintage” as of March 2016. But what does this mean? Here is Apple’s definition of the terms.

Vintage: Products that have not been manufactured for more than five and less than seven years ago. Apple has discontinued hardware service for vintage products with a few exceptions that can be found here.

Obsolete: Products that were discontinued more than seven years ago. Apple has discontinued all hardware service for obsolete products with no exceptions. Service providers cannot order parts for obsolete products.

Of course, in the world of Macs, obsolete doesn’t have to mean obsolete. And as for the Late 2009 iMac, it might be considered vintage, but it is still compatible with macOS Sierra so you will have access to the latest Mac operating system.

Upgrades Made Easy
Upgrading the hard drive or memory in your iMac is a great way to boost its performance and extend its lifespan. To see all of the upgrade options for your iMac, check out the My Upgrades search tool to find your specific model and compatible upgrade solutions!

* iMac capacities may very depending on the exact Model ID

OWC Newsfeed
the authorOWC Newsfeed
The OWC Newsfeed provides the latest OWC,, Rocket Yard, and industry news, information, and announcements for your reading pleasure and shareability!
Be Sociable, Share This Post!

Leave a Reply


  • Hi, I own a late 2009 Mac Desktop 27″, I have never used. I discovered it is considered vintage now.

    Now I want to use it and move all my windows files to this MAC.
    I discovered I have only 8gb… much more memory can I add? and do I need to replace all mem to make sure it all comes from same MFG or does it matter at all. (I read that somewhere)
    or should I just buy a newer Mac since this is so old.

  • Hi, I have an iMac Late 2009, I recently upgraded the memory to an extra 4gb that makes it 8gb, but the the Ram memories are at the speed of 1333 MHz and this imac supports upto 1066 MHz. Could the fact that i have inserted Ram speeds that are not compatible causing my iMac to keep crashing and restarting randomly. I currently am running macOS Sierra.

  • I ordered a mid 2009 2duo core refurbished mac. Apparently those were only sold to education facilities and therefore dont run as well compared to the late 2009 models. Am I going to have a very hard time running music softwate like FL studio on it?

  • Hi,

    I have a late 2009 21.5″ i Mac. It’s slow.

    I also have a 2011 21.5″ iMac but the graphics card is broken giving me pixelated sqaures all over the screen and occasional system freezes.

    I am considering putting the RAM modules from the 2011 into the 2009.

    Would this work or do I have to have the exact same modules for the 2009?

    I am also thinking of putting the 2011 hard disk into the DVD bay of the 2009.

    Any comments?

    Thanks in advance.

    • Hi Meirion, unfortunately, those RAM modules aren’t interchangeable, between those model years. In addition, the HDD in the 2011 model would be a 3.5″ drive, while the optical space an only accept a 2.5″ drive, in a Data Doubler bracket.

  • Hello There, I have a 2009 iMac 21.5” that is in good working order but I wish to upgrade to at least 1TB HDD or SSD whichever is best, would I have to upgrade the ram as well? If so how much to? and would it cause any technical issues and how much would it cost for this to be done. Roughly if someone was to fit it for me.


    • Hello, Linton! Upgrading the RAM is not a requirement when upgrading to an SSD, but can certainly be a nice upgrade to compliment the faster SSD! I would encourage you to reach out to our customer service representatives, they’d be happy to assist you in pricing for both parts and installation!

  • Can I upgrade my iMac to accept Photoshop, Adobe Creative Cloud.
    Recently signed up, cant install much/
    I have a late
    iMac (20 inch Mid 2009)
    Processor 2GHz Intel Core 2 Duo
    Memory 4GB 1067 MHz DDR3
    Graphics NVIDIA GeForce 9400 256 MB

  • I have an iMac late 2009 21.5″. It has 4GB memory, can I remove the 2-2GB memory and install 4-4GB? If so what is the easiest way to remove the 2-2GB modules?

  • I have a late 2009 21.5″ iMac running High Sierra. I recently bought a new printer which uses AirPrint to connect (a Canon model) and I cannot get it to work. Does Airplay/AirPrint work on a machine as old as mine?.

  • Hello, I have a late 2009 21.5in iMac. I upgraded to High Sierra some time ago and I noticed that my built-in CD drive no longer recognizes that a disc in present and will not play. Is this due to my High Sierra upgrade or something else? And is there anything I can do? Thanks!

  • Advice please. I have a 2009 iMac 27 and was wondering if a Radeon 6970 2GB graphics card (that is On eBay and show i7) work? Thank you. Theo (New Zealand)

  • I have a late 2009 iMac that has Sierra installed, but Mac will not allow me to upgrade any further. Consequently, I cannot upgrade any of my productivity apps (e.g., Office, Adobe).

    I am considering swapping out the HD for a 2TB SSD. If I do, will I be able to upgrade to Catalina?


    • Hello Jennifer!

      Thank you so much for asking about your machine. The late 2009 iMac is currently only compatible up to macOS High Sierra. At this time there is no option to upgrade further to macOS Mojave or Catalina.

      If you have any further questions, contact our Technical Support Team!

    • No. I upgraded to ssd and more ram but my video card and cpu need upgrading too. I have a mid iMac 2011 running high Sierra. Runs fantastic but I can’t upgrade the iOS until I upgrade more hardware.
      I have an amd video card and metal doesn’t support them.

    • Jennifer, go to this website it has a patcher that will allow you to upgrade to Mac OS Catalina I did it on my 2009 desktop works perfectly and allows me to install and run pretty much anything I want. the we address is

  • Hello

    I have a iMac 27” i5 mid 2010 model, my optical drive doesn’t work and the HD crashed all else on computer is good and it still looks new.
    Question should I install new Samsung 850 SSD and add 8 megs of Ram more to the std 4 that came with it and hope my computer can run as efficiently as the ones out now. I know an SSD drive is better than the Fusion drive they now have aren’t they? The optical dive I don’t need so I will just let it be. Should I do this to an old 10yr old iMac or get a new iMac. Will it last a long time or will it do no good and waste of time with it’s current operating system even with the SSD and ram mentioned.


    • Installing an SSD and increasing the amount of RAM you have will improve the performance substantially! Check out all the upgrade options for your iMac at, you’ll find every SSD and RAM option available for your model as well as install videos for everything.

      Also, if you don’t plan on using the optical drive any longer, you can swap that out for another SSD. It’s called Data Doubler, and you can check it out here.

      Hope this helps!

  • I always check with OWC before touching my Macs.
    I have been a customer since 2003.And, they have never failed me.

  • I have a 2010 iMac with 16 gigabytes of memory. Is there any way this can run the new iMac operating system (Catalina?). I can add more memory and it has plenty of hard disk space.

  • Hi… Your simple 3-step process doesn’t work for me. My iMac: 27″ Late 2009, 3.06 GHz DDR3 ..startup: Mac HD…Graphics ATI Radeon HD 4670 256 MB
    memory 4GB
    Serial: W89497XQ5PE
    This computer is not shown in your choices, for your upgrade tool.

    PS… no idea what a model identifier is.. Regards, Michael

  • I have an iMac 24 early 2009.
    Model Name: iMac
    Model Identifier: iMac9,1
    Processor Name: Intel Core 2 Duo
    Processor Speed: 2.66 GHz
    Number Of Processors: 1
    Total Number Of Cores: 2
    L2 Cache: 6 MB
    Memory: 4 GB
    Bus Speed: 1.07 GHz
    Boot ROM Version: IM91.008D.B08
    SMC Version (system): 1.45f0
    Serial Number (system): W89170K40TG
    Hardware UUID: 5FA4FD7A-0FE2-55AD-80BF-AFBDCB3A2E7C

    Can I upgrade – 1. Memory. 2. Mac OS – I have Snow Leopard 10.6.8. 3.Hard Drive 460GB to 1TB.

    Can anything else be upgraded?

    I had a PC before the Mac and I upgraded the PC to the Maximum that the Motherboard would take. Off=course the Mac is quite different.


    God bless


  • Thanks so much for the reply! I’ve been poking around all over and found a lot of conflicting advice. Can you fill me in on why the 2 x 4GB RAM should be moved to the upper slots (BANK 0 DIMM 0, and BANK 1 DIMM 0, right)?
    Thanks again!

  • Hello! I want to update the memory in my dual core late 2009 iMac from 4GB to 12GB. Currently, I have 2 x 2GB RAM that live in the two top slots. If I purchase 2 x 4GB RAM, should I install in the bottom two slots, or should each size pair live in its own bank together (one on top, one on bottom)?

    • Thank you for your question copo. You will want to move your current 2 X 2GB RAM chips to the lower slots and install the new 4GB chips in the upper slots.

      Please let us know if you have any further questions.

      • Thanks so much for the reply! I’ve been poking around all over and found a lot of conflicting advice. Can you fill me in on why the 2 x 4GB RAM should be moved to the upper slots (BANK 0 DIMM 0, and BANK 1 DIMM 0, right)?
        Thanks again!

  • Someone just gave me their old iMac 21.5″ late 2009 desktop computer. I’ve wiped it and recently installed the latest operating sys. macOS Sierra version 10.12.6, but now it barely runs. My question is- is it worth it to upgrade the memory or just better off getting rid of the thing? It currently has only 4GB installed.

    • Hi, India.

      You can still get good life out of your iMac. The late 2009 21.5″ model is upgradable to 16GB of memory, which would bring a significant performance boost. Here is a link to the proper kit:

      Another option to bring a drastic performance boost would be to add an SSD in place of the internal HDD, if it doesn’t already have one. Here is a link to compatible SSDs:

      Please let our customer service team know if you have any other questions!

      • Hi Jarrod
        Thanks for your speedy response! For the “drastic” performance boost” would I have to do both memory and SSD or just the SSD? And if I just did the 16GB of memory would that be satisfactory for just internetting and light photo editing?

        • Absolutely. Adding memory alone would be the easiest and most cost-effective way to increase performance during internet browsing and photo editing. Let us know if you have any other questions!

      • Hi Jarod, I purchased the upgrade you recommended but my iMac rejected it. My iMac beeped a few times, then went silent. After a few attempts to restart my iMac with the new RAM, I reinstalled my old RAM and my iMac fired right up. Any thoughts?

  • I have a 2010 27″ Mac that I replaced with a 2015 model when the hard drive died (Apple Store Tech diagnosis). I don’t have a pressing need for it; but, is there any reason to try to bring it back to life (with your expert help)?

    • Hi, Martin. A 2010 iMac can still be a great machine with the right upgrades. Please feel free to contact our customer support team, which will be more than happy to go over your options. As for reasons to bring it back to life, it can make a perfect hand-me-down or backup machine.

    • I had a 2009 27″ iMac that stopped booting when I was in the middle of a big project. I had a new iMac delivered the next day and put the 2009 on the shelf for two years. Last fall I took the busted one in to the Apple Store and found the problem was a bad video card, a cheap fix. I then replaced the optical drive with an OWC data doubler 1TB SSD and the 2009 Mac now performs better than my newer Mac. For a few hundred bucks I have a great machine. It was well worth it.

    • According to Apple, macOS Sierra requires at least 2GB of memory and 8.8GB of storage space.

  • Re: Upgrading to Sierra
    I have two mid-2011 iMacs that are running well on El Capitan. Both have max RAM and SSDs added behind the optical drive. It is said that the latest system isn’t always a good idea in an older computer that wasn’t designed to run it. Are these mid-2011s up to running Sierra without becoming sluggish?

  • Great article, and timely in my case. I just bought from OWC and installed 16 GB RAM and a 1TB SSD with the DIY kit in a 2010 21″ iMac that I picked up used for $400. The OWC DIY kit had everything I needed. Only thing additional was an external USB enclosure for the original 3.5″ drive. The OWC installation videos are great, much better than some of the other teardown/fixit sites that have only step by step pictures. If a picture is worth a thousand words, and a video is worth a thousand pictures, then how many words your videos worth? AWESOME tech support from OWC!

    Long time OWC customer, many DIY upgrades going back to G3/G4 days, thought the iMac case would be too tough to crack open after working in those massive desktop and tower cases of yesteryear. Your video shows exactly how easy it is. Now, can you make one to show how to replace the thermal paste on the CPU and video card heat sinks in an iMac? …

  • Question, I have an early 2009 24″ iMac. I’m thinking it needs a motherboard replacement. I would like to replace with say a board from a 2011. Is that possible? If not how new can I go? I also plan on replacing the 1TB with a SSD drive.

    • Thank you so much for your question! We are very sorry but we are not able to verify if a 2011 motherboard will be compatible with your early 2009 24″ iMac. We would recommend to contact the manufacturer for any motherboard upgrades or replacements.