Adding a Solid State HD to my iMac

It should be possible. I don't know how much space there is in the newer models to install a second HDD or SSHD. I would contact your local Apple shop because they will need to do the installation. If you do it yourself then you will forfeit any future support from Apple, and if you have an extended warranty in force it will be void.

Replacing the internal drive on your iMac is a very delicate

procedure. See tis to see what is involved:

http://eshop.macsales.com/installvideos/imac_27inch_late_2012_hd/

It is definitely a difficult task and as Kappy said, kiss your

warranty goodbye.

You may want to consider an external Thunderbolt alternative. SSD

performance can be nearly as fast as an internal drive.