MacBook Pro (2012 Non Retina) running slow after swapping HDD

[jwatters579]

Has anyone experienced this? I swapped the HD out of my iMac to my Macbook Pro. Both systems were running at a good speed prior. Once I did the swap, I noticed the Macbook was running slower (more color pinwheels, slower speeds trying to complete tasks, etc). Would it be a good thing to do a fresh install of OS?

 

[keysofanxiety]

Has anyone experienced this? I swapped the HD out of my iMac to my Macbook Pro. Both systems were running at a good speed prior. Once I did the swap, I noticed the Macbook was running slower (more color pinwheels, slower speeds trying to complete tasks, etc). Would it be a good thing to do a fresh install of OS?

Likely HDD SATA cable is on its way out. It's a very common fault on your model. Quite a cheap part to source and very quick repair. Ensure it's a brand-new genuine part rather than a refurb though.

If you haven't already, I'd recommend swapping with an SSD. Even with a fresh HD/OS install, the newer OSs don't run that well on a spinning drive.

 

[Fishrrman]

keys' suggestion about the cable is good advice.
You can test this by connecting the original HDD via USB, and booting that way.
Do you get a reasonably good bootup and performance afterwards?

Aside:
You should have bought a new SSD and put that into it, instead.
Will make A WORLD of difference.
You won't understand until you do it!