Early 2011 model, A1278 / 2.3 GHz i5 or 2.7 GHz i7 processor.

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SSD installed, HDD in optical bay - why's it suddenly so slow?

Hey guys,

So a month or so ago I replaced my HDD with a 120GB SANDISK SSD; wiped the original HDD and housed itin the optical bay; upgraded to 16GB RAM and did a clean install of the OS (now 10.10.3)

Since then, everythings been running like a dream and I've been bragging to everyone about how it's like getting a brand new MacBook for a couple hundred quid.

Suddenly though, everythings running super slowly, I get the spinning wheel of death every 5 seconds and it can't handle doing anything. This happened literally over night, out of the blue...

So far I've tried verifying both disks (all ok) and PRMC reset, which seemed ok. Neither helped... I have my final paper due in a week, pretty terrible timing - can anyone help?


Answer this question I have this problem too

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Do you have a bootable external disk which you can boot up with? If you do do that and run Disk Utility fixing the permissions & drive. But before you do make sure you have copies for your work just in case!

Last thing here is to go to the Startup control panel and make sure the correct disk is selected.

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Hey Dan, thanks for your swift reply. I should have been more clear - everything is working normally in spurts it's just impossibly slow.

I just booted an external ubuntu drive to check the status of the HDD and SSD and there aren't any errors reporting in either. Feels like a hardware issue but i'm totally stumped...


You'll need to boot up with Mac OS to use Disk Utility under it. Ubuntu won't properly check the GUID file structures.


You do understand some of the MacBook Pro's have an issue with the optical drives SATA ports speed. Review this note from OWC (it makes no difference who carrier you use as they all suffer from the same problem): Data Doubler. Note the Red notation at the bottom. Sadly, there is nothing you can do here unless you get a fixed SATA II (3.0 Gb/s) drive. Most SSD's today are auto sensing which won't work here.


Ah great, so it sounds like it could be the drive in the optical bay failing? Thanks for your help.


No, I wouldn't say the SSD is failing here. It's just likely the SATA port speed is mis-matched so you are seeing lots of retries as each read/write action needs to happen over and over again. This still is not good as you are stressing your system needlessly.


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Replace the HD/IR cable with a new 2012 cable.

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matt will be eternally grateful.
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