Just wanted to know if I could do this for my laptop. (2 hard drives)

[lukai]

Model Number: HP Pavilion Notebook - 15 - ab153nr

My laptop currently has 5400 rpm hard drive inside of it and it is extremely slow. One day, I was scrolling through Youtube and I found this video explaining how to add another hard drive or a ssd in place of the optical drive of a laptop. Desperate to make this thing any faster I was wondering if I could just get a ssd, put it in place of the optical drive then make it my boot drive. I understand I need a caddy and such, I was just wondering if this would be possible. Also, I do realize there must be some sort of bottleneck using this method since it's a SATA 2 port but I was going to get a cheap ssd for it anyways.

 

[popatim]

You'd be much better off using the ssd in the harddrive bay and putting the hdd in the caddy as often the optical bay is only sata1.
What you propose largely depends on if the manufacturer disabled having anything in the optical bay that wasn't an optical drive. In your case, I do not believe they have blocked it