I have a Macbook Pro 2012 (w / cd). Well, I had replaced the optical drive by one hand and everything worked fine. My main drive is a Samsung 500GB SSD with Majove. I found a 128GB SSD drive by HP at the desktop depot for $ 20. So, anyway, with the hard drive, my startup time was about 14 seconds. Now, with the 128GB, it hangs for a second and then opens the user disk. I'm trying to click on anything in the utility disk and it hangs again. I'm about to separate it and format the damn thing with my clone cable. Also, what is the best format for the 2nd disc. I will only store the source code on it.