Mid 2007 iMac with Fusion Drive
I just did this upgrade and wish I would have found this forum sooner. Regardless, I managed to get a Fusion Drive running with a EMC 2133 20" iMac (Mid-2007) with ML. It is not that bad at all price-wise and I feel was worth every penny of the upgrade given the performance results. My configuration involves the following:
1 - SSD (Crucial M4 - 256GB) - This can be found relatively cheap at Amazon.
2 - HDD (WD Scorpio Black 750GB) - Same place as above.
3 - I wanted the SSD as my main disk (disk0). Therefore, this piece is a perfect fit for mounting a 2.5" in the 3.5" HDD bay of the 2007 iMac -
http://www.amazon.com/gp/product/B005PZDVF6/ref=oh_details_o04_s00_i00
4 - Next, the optical drive adapter - this allows your PATA optical drive to be converted into a 2.5" SATA HD/SSD adapter and was found here -
http://www.amazon.com/gp/product/B0064A9Y5W/ref=oh_details_o05_s00_i00
It was not the most perfect fit but it works and it beat the 60$ some other website is asking for.
5. Finally these websites served as perfect guides that got me up and running with a brand new Fusion Drive OS in no time:
A:
http://www.ifixit.com/Guide/Installing+iMac+Intel+20-Inch+EMC+2133+and+2210+Dual+Hard+Drive/8951/1 - This is for installing the second drive in the optical bay (where I put the 750GB WD SB)
B:
http://www.macworld.com/article/1167857/how_to_make_a_bootable_mountain_lion_install_drive.html - This is how I managed to get 10.8.2 bootable onto a USB drive (now that there's no optical drive.)
NOTE: 10.8.2 is required to get Fusion Drive enabled.
C:
http://www.macworld.com/article/2014011/how-to-make-your-own-fusion-drive.html - This will be the final step before you install the OS - it guides you through creating the Fusion Drive - which worked flawlessly.
TRIM isn't necessary for the M4 SSD (it has its own garbage collection) but it also doesn't hurt to enable it. Unfortunately Apple doesn't outright support it on 3rd party SSD's so every major OS X upgrade will require a new fix. However, for 10.8.2 the TRIM enabler commands can be found here:
https://gist.github.com/clarencesong/3768688
I get the same 25 sec boot time and now waking from sleep is under 1-2 seconds! The great thing about Fusion is you get the SSD speed with the 1TB total storage - the OS handles all the transferring of data between drives in the background.
For around 300$ total this is a good deal considering my almost 6 year old iMac is still relevant and will be for at least another 4 years.