I just received a MacBook Pro from somebody else because it was running too slow. Booting up takes about 4 minutes.

I have tried formatting the drive and reinstalling the operating system from scratch. The reinstall takes about 8 hours and in the end it doesn't work, or boot up is just as slow as it was before. The computer especially seems to run slow while doing system/hard drive things with it.

I want to know if getting a new hard drive will fix my problems. Is there a way to test my hard drive to know for certain that it is the problem? I don't want to waste my money on a SSD if it's not even going to make a difference.

I've live booted Linux on which runs beautifully on it which is why I'm thinking it is probably the hard drive's fault.

Here are some more details about the MacBook Pro:

  • OS X El Capitan
  • Version 10.11.3
  • MacBook Pro (13-inch, Mid 2012)
  • Processor 2.5 GHz Intel Core i5
  • Memory 4 GB 1600 MHz DDR3
  • Startup Disk Macintosh HD
  • Graphics Intel HD Graphics 4000 1536 MB

4 Answers 4


I have the same model of Macbook which was showing the same issues. After replacing the Harddrive with an SSD I still had the same issue.

It ended up being the SATA cable connecting the hard drive to the logic board. Over some time the insulation had started to wear off and the cable was occasionally shorting against the base of the case causing IO errors. Once I replaced the cable these errors stopped happening.

A good way of checking this would be to use an external USB to SATA cable and try and boot the laptop from it externally. If the drive functions well when doing this then it is likely the SATA cable that is at fault.

  • 2
    How did you diagnose the origin of these errors?
    – dan
    Commented May 3, 2016 at 11:25
  • The diagnosis for this was mostly through prodigious googling! I was worried after I had replaced the HD (and indeed RMA'd the replacement!) that I was still getting the same errors. I found a number of threads on the apple support forums which suggested that the cable could be at fault. Commented May 3, 2016 at 11:30
  • 2
    I've had the very same issue with my SATA cable. The most effective way to diagnose it is to take out your hard drive and use a SATA to USB cable to boot it. If it's running all fine then you know your cable has gone bad. Also, those are known to be prone to failure.
    – Simon
    Commented May 3, 2016 at 11:39
  • Do you remember of the scheme of errors you had in /var/log/system.log?
    – dan
    Commented May 3, 2016 at 16:36

I have the same MacBook Pro. I did the following:

  • I bought a SSD and replaced the hard drive disk. I installed OS X on the SSD. (240 GB - $100).

  • I inserted 8 GB of RAM (replace the two 2 GB RAM) ( 2 x 4 GB - $50).

  • Then I replaced the SuperDrive with .... the old HDD. You need to buy an adapter. (Adapter on Amazon - $30).

Yes it's expensive, but it takes 10 seconds to boot (password typing included).

Because new operating systems increase the access to HDD and the original HDD in the MacBook Pro, Mid 2012, is only 5400 RPM, it may be slow.

  • About how slow was it before? Commented May 3, 2016 at 7:33
  • 1
    About 3 to 5 minutes to boot, and because I use virtual machines it was really slow during the use.
    – Chris
    Commented May 3, 2016 at 7:35
  • There is no evidence you had the same problem as Nathan Bierema.
    – dan
    Commented May 4, 2016 at 13:26

First, Some Diagnostics

While SSD's will give you a boost in speed simply replacing one with the hopes it solves a problem could get expensive. Let's verify that the problem is the drive in the first place and not something else.

If you can log into your system, open Terminal and issue the command

diskutil list

You will get a listing of all your drives on that particular machine. Find the one that corresponds to your boot drive. Chances are it will be /dev/disk0 but you will want to make sure.

Next, you will want to get the SMART status of the drive. Issue the command, substituting your drive label if different

diskutil info /dev/disk0 | grep -i smart

If you get anything other than "Verified," your drive is in the process of failing and it's time to replace it.

Next, download a drive utility App like DriveDX that will give you in depth diagnostics about your drive.

If everything passes there, it's time to look into Apple Hardware Test. It involves disconnecting everything but your mouse and keyboard, and while booting from a powered off state, hold down the D key. Choose to "Perform Extended Testing" If it provides you with an error, make note of it so you can provide it to us. Also, be sure to visit the link I provided for details.

How to Fix...

Chances are, it's going to be your HDD, but you want to do diagnostics first so you're not spending time and money trying replacing a drive when the problem is your logic board. According to Everymac.com, your MBP came with a 500GB SATA HDD

enter image description here

That spinning drive is now at least 4 years old and is close to EOL. If it turns out that your drive is failing, it's pretty easy to replace with an SSD. To see how to replace, take a look at this post that already details how to do this: My Mac is getting really slow, what should I do?

While You're There...

Everymac.com also lists your max memory as 16GB. You should consider upgrading your memory as well given how cheap memory prices are today. For your specific Mac, I found this Kingston 8GB Module (you will need two).

enter image description here

If it's Your Logic Board...

If you run Apple Hardware Test and you come to the conclusion that it's your logic board, you will have to start making some decisions whether you want to repair/replace your logic board ($300 to $700). Depending on exactly what is involved, it may make sense to just part out the MBP and purchase a new one.

  • 1
    First, some diagnostics :) !
    – dan
    Commented May 4, 2016 at 13:29
  • I love it when people immediately go into a solution when no diags have been performed. It's like saying your car is running poorly, so the answer is replace the transmission.
    – Allan
    Commented May 4, 2016 at 13:59

You will diagnose that you have a serious disk problem by looking at


and more specifically with:

grep disk /var/log/system.log

These error messages will clearly show if your disk is producing I/O error on the same location, which will indicate a disk problem, or on multiple locations which will indicate a bus or logic problem. I have not any evidence of an OS or software which is able to disambiguate these 2 kinds of problems.

I want to know if getting a new hard drive will fix my problems.

From the information provided thus far, there isn't the smallest evidence that your problem is coming from your disk. In term of probability, if your MacBook Pro didn't receive too many vertical shock (falling on the desk or on the ground or running on board of train or plane) your disk is 2 years away of its deadline (I estimate it to be end 2017).

  • 1
    This is somewhat unspecific. Commented May 3, 2016 at 16:08
  • I don't have a damaged disk at hand to provide typical examples and the related analysis. •••• If you have one and provide the associated error messages, I will provide an analysis.
    – dan
    Commented May 4, 2016 at 13:10

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