I have an Aspire E5-551 that I recently upgraded. I replaced the stock hard drive with a Crucial SSD and maxed out the onboard RAM (came with 6gb, now has 16gb). The system is blazing fast now. Right now, I'm using the original HDD in an external USB enclosure for storage. I wanted to look into the feasibility of putting the storage HDD onboard by means of a caddy that fits into the side bay that would otherwise fit the optical drive. I have been able to find all kinds of options for the parts for this, but I wanted to check with the folks on this forum to see if anyone has ad any experiences with this idea and how well it works. Any info anyone can pass along would be helpful. Thanks.