Hi mac followers! I bought an iMac 27" mid 2011 straight when it came out, and i got 1TB hard drive inn it and nothing else. Afterwards I've upgraded the RAM and now i want to upgrade my hard drive. So what I'm thinking is, replace the main hard drive with 250GB SSD and add a second 250GB SSD inn the free SATA slot. I've been frustrated with the noisy and slow 1TB hard drive now for a time. So I have been googeling like CRAZY these last days to get the right guides and tips on how to do it the right way. I found these guides that im going to use: This one for replacing main hard drive! - http://www.ifixit.com/Guide/Installing+iMac+Intel+27-Inch+EMC+2429+Hard+Drive/7555/1 And this one for adding a second SSD! - http://www.btobey.com/learn/imac-ssd-install.php I've bought the cable and adhesive tape for the second SSD, so that is all ready. My consern is the replacing of the main hard drive. By that i mean the fan nois problem. I've been reading like crazy about it to find the best way to get around that. If i understand it right, there is NO extra cabel that is the heathing sensor, it is now within the software of the main hard drive thats is approved by Apple them self. I am guessing the ones i bought, is not approved by Apple. BTW I bought 2x A-Data XPG-Series SX900 250GB to put in my beauty. So I asked a fellow mate that has been replacing hard drive on many iMacs about the fan problem, and he said he knew what to do. So he said that i should short the sensor cabel that is going inn to the SSD. By that he means that i should cut the cables, take of the rubber and tape the 2 wires togheter so it tricks the iMac to think that the sensor are OK, but really arent. Not cut all the cables, just the 2 at the smallest connector to the main hard drive. Can anyone confirm if this will work? Got all my iteams today, so want to get it all right before i start opening my iMac. I am also going to install Windows on my iMac, so i really need to know if this is going to work.