I have a 2011 27-inch iMac w/ 3.4 GHz i7, 32 GB of 1333 MHz DDR3, and the 2 GB 6970M. This iMac came with the 256 GB Toshiba SSD from the factory, but the speed was inadequate, especially compared with the latest gen SSDs. I also owned a Samsung 840 Pro 256 GB SSD, that I installed in the iMac for awhile, but I eventually put the factory SSD back in due to the lack of TRIM support. I began the hunt for a faster, more compatible, and larger capacity SSD to install in my iMac. I knew that the 2012 Mac Minis and Macbook Pros (non-retina) could be configured SSD only. I also knew that they were using SSDs based on Samsung's PM830 controller, which is comparable to the retail Samsung 830 series, which has performance comparable to the Samsung 840 Pro SSD. I could not find any Apple Technican Guides for the 2012 models of Mac Minis or Macbook Pros, so that I could get the part number for the SSD-only option. (After finally receiving the SSD, I now know the part number for the 512 GB Samsung PM830 based SATA 3 SSD is 605-3211). I was able to score one off eBay the other day for $360. Which is a pretty good deal for an Apple-suppported, Samsung based SSD. A 512 GB Samsung 840 Pro would run you about $480, and if you could find one the Samsung 830 would still cost you well over $400. TRIM is supported out the box, and Blackmagic disk test comes back about 463 MB/sec Write, and 513 MB/sec Read. The SSD was brand-new, never opened or formatted. The seller who I brought the drive from on ebay is omeeze. After checking her feedback, she's hosted quite a few auctions with the same SSD, all with positive feedback. Just thought I'd share my experience. I've attached a screenshot of my System Information about the SSD.