Installing an SSD in 20" early 2008 iMac


Hi there

I want to breath some more life into the 20" iMac that our daughter is using for the odd kids game, YouTube etc. and in order to do this I’m thinking that putting an SSD in it may be the best option.

Has anyone in the forums had an experience with doing this on a machine this old? I know I’ll need some sort of adapter in order to install the SSD as the iMac uses 3.5" HDDs - are there any recommendations on this also?



I’ve put SSDs in Mac Minis of that vintage and older and it definitely makes a worthwhile difference. I don’t know how hard those iMacs are to get apart, but assuming that’s not too difficult, it should be well worth doing.

The SATA 2 (3.0 Gbps) bus in this machine is fast enough to make a huge difference to the machine’s I/O performance, but you don’t need a super high performance SSD to get that. Anything that meets your other requirements for quality should be fast enough, so you could think about getting something that will be good in the next computer. Most people still seem to recommend the 850 EVO and the 250GB has a good price per GB.

There are a few 3.5" to 2.5" adaptors available. I have used an older version of this:


Been there and done it with an early 2008 iMac. I used the RamCity site to select the SSD and iFixit for instructions on how to do it.

I also found on RamCity that I could have 6GB RAM, even though Apple says only 4GB.

The combination of the additional RAM and the SSD provides amazing performance.


Thanks for the feedback, I think I might just bite the bullet and do this in a couple of weeks time (or maybe sooner).

I’m looking at using this drive and bracket:

So all up I’ll be able to get it done for under $100 (NZ) which would be great.


It does indeed, though I’ve noticed that extra RAM makes considerably less difference once you have an SSD because the swap file is so much faster.


SSD in that machine is a BIG upgrade, but remember you can’t go past 10.11.6 so don’t pour too many $$ into it.


Good thought jaysee.

I did my upgrade about 3 years ago. I regret that I did not do it earler.

Now I have this iMac that quickly does all I want to do, but It will lose support later in 2018.

The El Capitan support status is “Security updates and printer drivers only. Extended support to end in 2018, and iTunes support ends in 2019”

I could keep using it, but it may become vulnerable to malware etc. with no more updates. It is difficult to evaluate what risks are involved in the continued use of a 10y old computer.

It would be a shame to retire a perfectly functional computer.

I wonder how many Macs are still in use in this situation, running an OS older than El Capitan.


Quite a few. Particularly iMacs as they seem to outlive their notebook counterparts. My own machine is running OS X Yosemite, and it’s still as capable as ever.

macOS Sierra and macOS High Sierra are just as susceptible to malware as Yosemite or Mavericks, primarily because instead of exploiting vulnerabilities in the system, malware often relies on deception to convince the user into installing the software manually. MacKeeper for example tries to convince the user that it’s beneficial for the performance of the machine. Other malware like Genieo and VSearch come disguised as Adobe Flash Player updates. These run within the user space and are the most likely employed method to catch out a user and take their sensitive information.

Other vulnerabilities, like oversights that allow for unrestricted access to protected memory spaces or allow arbitrary code to be executed, are in theory more prevalent on older operating systems than newer ones. That said, newer systems and software updates can have bugs and vulnerabilities of their own, so some degree of vigilance is required whenever sensitive data is involved even when running the newest software.

Of course it depends on what the machine is used for, but generally speaking for a daily use machine where the user is relatively knowledgeable about the risks associated with being online, where not to be and what not to click (and install), I would have no qualms about using an older machine with a somewhat older OS.


I did a 2010 Mac Pro an upgraded the graphic cards a few years back. Worth the effort and made an amazing impact on performance. Like having a new PC.