MacBook Pro suddenly running very slow


macrumors newbie
Original poster
Apr 19, 2017
Hi there,
my MacBook Pro is running super-slow lately. Mostly I use it for music production, and it was working fine until now. I recently erased my HD and reinstalled macOS, but the problem still occurs. It works quite well until I start CPU-heavy processes, like Ableton Live (I used to be able to work with much bigger projects without any problems though), but then I even have a hard time trying to close the application, because the computer suddenly becomes that slow. I‘ve tried different versions of Ableton, didn‘t help.
Thank you for any solutions in advance,

MacBook Pro (13-inch, Mid 2012)
macOS Sierra
2,9 GHz Intel Core i7
8 GB 1600 MHz DDR3
Intel HD Graphics 4000 1536 MB



macrumors G3
Nov 23, 2011
You would vastly benefit from an SSD, though it's likely that the HDD and/or HDD SATA cable is also failing.

The HDD failing cable is a documented issue on your model and there's a silent repair program to replace these. They corrode over time from dust and air alone, so based on the age of the machine alone it's very likely that's failing. Any Apple Store or AASP can sort this out free of charge. Similar story with your HDD (wear/tear on platters).

You can run SMART Utility to verify the hard-drive is OK:

If SU shows CRC errors only, this would 100% confirm a failing HDD cable. However even if you don't get CRC errors, the HDD cable may still be failing.


1) Check/screenshot SMART:
2) Pop into an Apple Store/AASP so they can check the cable
3) Upgrade to an SSD -- even if the HDD is OK, an SSD will vastly improve performance and longevity on your machine, especially useful when using DAWs.
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macrumors 604
Oct 24, 2013
As above sounds like a hard drive or sata cable or both, at 5 years old you are reaching the end of the HDD life anyway so I would replace both, I would also replace the HDD with an SSD they are now very affordable and will make your machine better than new.


macrumors G3
Nov 23, 2011
run the SMART Utility test, i assume it‘s the HDD cable
thank you guys, it has been a big help!
It's both! A load of CRC errors indicates the HDD cable is failing. 8 pending bad sectors and 4 reallocated sectors means the HDD itself is failing.

1) Pop to an Apple Store/AASP, get a new HDD SATA cable fitted for free.
2) Swap out HDD for SSD.
3) Good as (well, better than) new!