2015 iMac Very Slow (Solution)

So, I like many others came here because I was beyond frustrated that my new 2015 iMac with an I5 processor, but only 8gb Ram was running so slow, like ridiculously slow!!!! I was getting Geekbench scores of over 12,000, but yet even the most basic things were taking forever to complete. I did my searches and came across the solution.

I wanted to share so others can learn quickly how to correct the issue.

As we know, the Hard Drive, in my case a 1TB fusion drive, and RAM are not user upgradable due to being soldered to the logic board. The solution, is add an External SSD Drive and use it for your System Drive.

I bought this:

StarTech.com USB 3.1 Gen 2 (10Gbps) Dual-Bay Dock 2.5"/3.5" SATA SSD/HDDs - Supports SATA I, II, III UASP - Top-Loading

https://www.amazon.com/gp/product/B00XLAZ9KC/ref=oh_aui_detailpage_o01_s00?ie=UT F8&psc=1

From what I understand, a Gen 1 USB 3.1 is fine, but I bought the most recent as it was inexpensive.

I already had an extra SSD from a previous upgrade in my MacPro, so I reformatted it, and used Carbon Copy to make a bootable copy of my System drive in my iMac. After all that was done, I told the computer to boot from the external SSD Drive from now on. Done in System Preferences, under Start Up Disk.

Now my iMac screams, its super fast!!!! Apps fire up insanely fast, and now I have the computer I expected and even more!!!!!!!!!!!

Is crazy that we have to do things like this to new computers, but Apple charges extortion prices to upgrade the System Drive as well as RAM in their new computers when purchasing......

Hope this h helps all of you struggling from the same slow performance I have been experiencing until this fix!