Hi MRers, Brand new 15 inch 2012 cMBP, I am trying to install ML on a Crucial M4 256 GB SSD, installed in the optibay using a Nimitz caddy. I also installed 16 GB Crucial RAM at the same time, which seems to be functioning normally. I made a ML installation USB stick according to the various instructions around the web. No probs there. But when I re-boot, and select the USB stick to commence the installation, the installation process is taking forever. I mean, it says (after about 20 minutes of the progress bar barely moving) that estimated time is over 4 hours. And it's been like that for half an hour already. I think the SSD is fine. It mounts normally when I boot from the HDD, and I did a BlackMagic test and it was hitting 450 MB/s read and about 250 MB/s write - sounds pretty normal for an M4. System profiler says it has a negotiated link speed of 6 gbit/s. At the moment I will just leave it overnight and see what happens. But does anyone have any clue? This is not right - even on a HDD, it should only take 30 mins or so. Pretty sure the USB stick is fine, I have used it in a previous ML installation without dramas. One option is to swap the SSD and HDD over, but not desperately keen to open her up again, and I don't really understand why that might be the problem. Thanks.