Ridiculously Slow Macbook Pro 15inch Early 2013 I stumbled on other posts about the Ridiculously Slow Macbook pro 2013 That were remedied by replacing the harddrive cable. I am dealing with agonizing sluggish behaviour on my mac, It seems to be the same issue  however as you know 2015 macbook pros have SSD's.. do you think its about replacing my SSD as opposed to a cable swap.

I am desperate for help, I can't use my computer... 

can you help me figure out what to do?
I have yet to see a horrible, measurable slow down, but that is exactly what is expected as SSD wear out. 


What happens at the user/OS level when an SSD finally wears out?


If you have an easy SSD handy to swap, I would get a black magic disk test benchmark before and after the swap.  

If you don’t, perhaps get a benchmark of disk IO and then erase the drive after backing up and repeat the test in a fresh os install that is mostly empty of user data. 

Once you can post some specific read and write speeds, that would let other people chime in if you're in the same ballpark for speeds.