MacBook Pro late-2011 slow and unusable after Yosemite OS X clean install

I agree in general. But my experiences with these 5 disk tools that 4 did nothing else than reading the s.m.a.r.t. data , except for DD that did a number of calculations as an extra. the 4 did not find anything wrong, DD did find indications (not proof), and in my cases it was right. (perhaps coincidence, perhaps luck, perhaps a little bit of educated guesses). That does by a long way not mean that it is infallible. I am curious what the developer thinks about this test of today. Thanks for your help here.

greetings, Lex.

If I can shelve the disk tools conversation for a moment.

One of my clients had exactly the same problem with a 2011 MBP that was as Apple configured out of the box. The machine went from usable to unusable as a result the upgrade. I did a complete erase (including partition) and started again using USB disc to boot. Once the install of Yosemite had completed, the machine restarted and ran like a dog. I then left it on overnight doing nothing (as I thought) and came back to it the following day and it was running like a train. My immediate thought is that indexing and other 'housekeeping' activities take place that are not easy to monitor. Certainly the 'wait after install' has seen activities kick off after a period of time, and the MBPs that I had in for slowness issues have all been sent back to their owners after 24 hours and have not come back.

Now going back to the disk tools, and no disrespect to any author etc. If you have a machine running self-diagnosis it is not a clean test and RAM issues may simply cloud hardware flakes in the background. The only way I test a drive is by slaving it off a known solid machine. Disk tools offer a good insight, but cannot be seen as a solid diagnostic unless you do it from another machine that you know is good. SSDs are a brilliant way to speed up your machine, but they are not immune to disk-style issues and quality is everything. You also need to ensure that TRIM is supported, but that is another thread for another day.

I hope this helps.

Can someone of you possibly help me with the following situation? I am assuming it is the same problem as the posts in this topic.

I have a Macbook pro late 2011 (2,4Ghz i5, 8GB RAM) running Yosemite without any problems.

Another Macbook pro early 2012 (2,5Ghz i5, 8GB RAM) was running terribly slow before the upgrade to Yosemite. I thought doing a fresh Yosemite install would have this one running like new, so formatted the drive and clean installed Yosemite using the recovery over the internet. Installation took an awfully long time (about twelve hours) and after installation the machine was still running very slow. Beachball appearing for several seconds nearly after every click or operation.

I thought the issue might be hardware related so I placed the harddrive of the 'slow' one in the good one and tried to reinstall Yosemite on the harddrive. This time install went fine (30 minutes) and machine ran perfectly so I am thinking it cannot be the HD that is failing. Furthermore I placed the good harddrive in the slow macbook and it ran slow too. Also tried to swap the RAM memory of both machines and the issue remains, so no faulty RAM either.

I was hoping anyone of you has encountered the same issue and knows of a possible remedy. I tried resetting the PRAM and NVRAM, filevault is not active either and permissions were repaired. ETRE check and Apple hardware check monitored nothing out of the ordinary either.

In conclusion: I have two almost identical MacBooks, the older one is running fine and the most recent model is not running as it should. By swapping the HD and the RAM I can say I'm pretty sure it is not related to either of those components, but I have no idea what it could be aside from those.

1) Please start your own threads. Don't piggy back on someone else's months-old thread.

2) Don't EVER update a machine that is already having problems. That will ONLY make it worse. Just installing Yosemite will significantly slow down a machine.

3) If you want to run EtreCheck, the idea is to start your own thread and post the contents. What is the point of using an online tech-support forum if you are going to do your own diagnostics and declare that they are nothing out of the ordinary?