Which solid state drives are compatible with iMac 7 27 inch late 2009?

Question

I am interested in installing an SSD (120 to 250gb) for the start up drive and run the system and apps that are disk drive intensive like databases.  My goal is to speed up my iMac 7, and of course, minimum investment necessary.
I searched online and find lots of material at OWC, Crucial and iFix it but have found conflicting opinions and even success in the upgrade.  So my questions are:
1) Can an SSD be installed in my iMac?  iMac 7 late 2009, 2.8Ghz 27", model 11,1, 16GB RAM
    a) as an internal hard drive in addition to the factory installed?
    b) as an internal hard drive in replacement of the factory installed?
    c) as an external USB drive?
2) What type of SSDs are compatible?
3) Assuming that 1 and 2 are positive, what are the most critical things that I should keep in mind when transferring OS X and the boot drive location from the current drive to the SSD?
Any guidance, no matter how partial is greatly appreciated.
Thank you.

Answer 1

I put an OWC SSD drive in my late 2009 21.5" iMac. Note that your model computer has a link speed limit to 3G, so putting a 6 G will not give you more than 3G link speed. Furthermore, putting a 6G SSD in this model might also throttle down the actual speed to 1.5G. Not sure about other model drives, but that is noted in the fine print at OWC. Read the compatibility issues for your model computer, especially about the link speed issue
There is also the issue of the temp sensor which is located internally on the hard drive for this model and later. So you will have to make special adaptations to install any drive other than direct same type compatilbe replacements in the main bay. OWC also sells an adapter sensor cable for this, but I think it cost around $45.
One thing that drove me to OWC was the fact that they do not recommend using TRIM with their drives. That is a debatable issue about using TRIM with other drives, so if you go with another brand, you might want to research that topic before choosing another brand other than OWC. Many have stated no problem without using TRIM enabler software using some of the other brands like Samsung SSD drives.
What I did is left the internal drive in the main drive bay and installed an OWC SSD in the optical bay using the data doubler adapter. This has worked out great for me and I use the main drive as a backup drive. There are several sizes available in the 3G model. I chose the 240gig.
The whole kit with the data doubler is in the link here:
http://eshop.macsales.com/item/OWC/DDIMSSD240/
Not saying you will get blazing performance with this like 6G compatible speeds would give, but as I said, your computer hardware is limited. But your sustained Read/Write speeds will basically double, and the Random Read/Write will go up tremendously.
You will definitely be pleased with the performance increase.
Once I installed the drive, I just used Disk Utility to format the SSD drive and then restored the whole internal drive to the SSD drive. Everything copied including the recovery partition to the new drive. Once the restore was done, just changed startup disk and booted into the SSD. Was very simple.