Hi, have searched for the answer for days now, and seems to be allot of different views on this. First which SSD drives will work, without the fan going bananas, and does it have a pcie socket on the motherboard that can be used for SSD, or is it only for Apple branded SSD drives? Looking to get minimum 500gb, not big fan of Samsung, so am thinking about Sandisk SSD drives, or other brands to consider, looking for maximum speed at best value. It is a base model iMac ultimo 2013, with only 5400rpm spinning hard drive as standard. Am also considering just getting a USB 3.0 SSD (thunderbolt too expensive imo), and use it as system drive, much easier that opening up the iMac, how reliable would that be in the long run, with like Sandisk Extreme 500 USB 3.0 SSD drive?