iMac is underperforming - help!

Discussion in 'iMac' started by Zacu, Apr 28, 2015.

  1. Zacu macrumors newbie

    Apr 28, 2015
    Hello fellow mac-users!

    I have had some troubles with my iMac for quite some time and I have reached the point where I am clueless as to why my iMac is running so poorly when its nothing but a powerhouse!

    So I made this account hoping some of you guys out there can help me out, so heres my story:

    When it was brand new I bought an iMac (medio 2011) with a 3.4Ghz Quad-Core Intel Core i7 with AMD Radeon HD 6970M (2GB ram). Additionally I have replaced the standard ram with 16GB 1333MHz DDR3 SDRAM and replaced the CD-rom with a 128GB SSD Samsung 840 PRO HDD where I have installed my OSX on.
    The standard 1TB HDD is still inside, working as an extra storage.

    So, as you can see - my iMac might be 4 years old, but its rather powerful for an iMac.

    The problem is that its underperforming so much! I used to be able to play games (Like WoW, Heroes of Newearth, Counter Strike: GO, Hearthstone etc) without any problems in fullscreen mode with highest options enabled. Having 2+ applications (games as well) open and running at the same time used to be NO problem AT ALL - nowadays I cant even play Heroes of Newearth while being on Skype and have my Google Chrome browser open in the background. I have to play WoW and Hearthstone in Windows mode, because fullscreen mode tears my iMac apart.

    I installed Counter Strike: GO just to see if I could run that without problems, but as I feared - I went into a game and saw that instantly that it couldn't run smooth either (and that game is really nothing...).

    So I started playing with the idea of selling my iMac and buying a new one, but lately I have had second thoughts because the new iMacs aint even that much of an upgrade so I am worried that it will give me the same problems if I bought the new one.

    So my friends on their stationary windows machines with mediocre specs can have all the games mentioned above open at the same time, ALT+Tab'ing between them without any trouble whatsoever - and here I sit on twice (if not more) as expensive machine with better specs and is unable to play if I forget to CMD+Q every application before I go into a game.

    What is wrong? I have tried to completely clean out my SSD (where OSX is on) deleting everything unnecessary and keeping like 30GB free storage. But it doesnt change anything.
    I have thought about totally format the drive and install everything again from scratch, but its not more than 6 months ago I put the SSD into the iMac and ran the OSX on that - I have a hard time believing the SSD causes the problems because it problem was there long before I switched over to the SSD (which also were one of the reasons why I installed one into the iMac in the first place).

    Can anyone help me? I am desperately in need of something, because I dont want to go away from mac and OSX but as it seems right now I am almost forced to do it... :(
  2. keysofanxiety macrumors G3


    Nov 23, 2011
    Hi Zacu,

    This seems like a tricky one. Few things that I'd try would be:

    1) Check HDD/SSD SMART data. This will very quickly show if you have any corruptions on your drives. I use SMART Utility ( though you're welcome to use a different one.

    2) Run volume verification through Disk Utility (Applications>Utilities>Disk Utility). Single-click your volume (by default called Macintosh HD), and click 'Verify Disk'. If there's an issue please let us know, we'll take you through how to repair that through the recovery partition.

    3) Check Activity Monitor (Applications>Utilities>Activity Monitor). Is the memory pressure high or is there a swap used? If yes, all you simply need to do is shut down the computer to clear the RAM (Apple menu>Shutdown). To ensure that all background processes are closed on restart, please disable the option 'Reopen windows when logging back in'.

    Also did you do a fresh install on your SSD or used Time Machine backup/cloning software?

    EDIT: Please can you quote this so I get a notification when you've had an opportunity to run through some of the troubleshooting? That'll allow me to quickly respond to you so we can try a few other things.
  3. Zacu thread starter macrumors newbie

    Apr 28, 2015
    Thank you for your time to read and answer my problem! I will do the above and get back to you ASAP.
  4. Zacu thread starter macrumors newbie

    Apr 28, 2015
    All right:

    I installed SMART utility and ran it on both my drives and both PASSED without any errors or troubles for that matter.

    I went into the Disk Utility and clicked the "Verify Disk Permissions" and after that was completely I clicked "Repair Disk Permissions". After that I clicked the "Verify Disk" and it stated everything was good - so I couldn't click the "Repair Disk".
    I did this on both Disks (1TB HDD and 128GB SSD)

    I am shutting down my iMac everyday so I dont think thats the problem, but I went into the Activity Monitor and saw that no swaps were used and I have stored around 4GB at that moment, so I went ahead and shut the computer down and now it says 2.66GB. (I have 16GB in total)

    So what now? :)
  5. keysofanxiety macrumors G3


    Nov 23, 2011
    Hmm, okay. You advised that the SSD is in the ODD bay. Is it definitely booting into your SSD rather than the HDD? When you first start your Mac and hold the 'Alt' key, does it display two Macintosh HD partitions, or did you wipe the HDD? At any rate I'd recommend putting the SSD into the HDD bay, and the HDD into the ODD bay.

    You can also try reset the SMC. To do that: shut down the iMac, unplug the power cable for 15 seconds, pop the power cable back in, and turn it back on.

    You can also try reset the PRAM. If you have a white boot screen for about 15-20 seconds before the Apple logo (normally after doing a hardware replacement), this resolves the issue. To reset the PRAM/NVRAM: Turn on the iMac, then immediately press and hold the following 4 keys: Cmd, Alt, P, R. Continue holding until you hear the Apple 'boot chime' 3 times, then let go of the keys and allow it to boot into the OS.

    The next thing to try would be to download and Memtest ( Next, shut down the Mac. As soon as you turn it back on, press and hold Cmd+S to boot into single user mode. Once it's there, type memtest all 10 and hit Enter. This will run 10 passes on the RAM. If there are any issues detected, it is the RAM. Please be aware that this will take some time to do, so I'd run this before you go to sleep one day or something.

    Other things to try maybe to monitor the GPU temperature - due to the age of the machine it's possible that a build-up of dust or worn thermal compound could be causing the GPU to overheat and therefore throttle performance. That's just stipulation though, we can try a few other things. Not sure iStat Pro is free any more so if there aren't any issues detected after the above troubleshooting we can source a different temp. monitoring application.

    Speak soon.
  6. Zacu thread starter macrumors newbie

    Apr 28, 2015
    Did all the things mentioned above without any problems and still the machine is underperforming.

    I have come to the conclusion (after reading a lot on this forum) that the 27" 2011 model is really one of Apple's "black sheeps" with lots of heating issues etc.

    I have had my GPU burn down after the first year of having it, and ever since I have noticed that the screen on top corner lefthand side is so hot that you can boil eggs on it. I think all the heat is slowing all components down inside the iMac and thats why its slow og underperforming.

    Can anyone agree to that? I have always loved this iMac (it was my first) but on the other hand the heating issues have always bothered me from day one - and I think its biting me in the tail now!

    Its out of warranty, so I guess I have to get rid of it and make a new battleplan for what to have next.

    I have been looking at the new iMacs currently available on apples website, but I am terrified that those machines will have the same problems etc.
    iMacs aint for gaming, and I consider myself using it for that AS WELL - but not much (I mean, the games I play is not heavy at all - its just casual games without extreme requirements to play) - so right now I wonder if I should get a new iMac at all?

    On the buyer's guide here on this website, it says "Caution" as well on buying iMac at the moment - so I guess thats not the greatest idea to do tomorrow?
  7. keysofanxiety macrumors G3


    Nov 23, 2011
    Hi Zacu, I guess the last thing to try would be a clean install. However from what you've described, the issues are synonymous with the graphics card running a little hot. If you're in the UK, the out-of-warranty price for Apple to service the cooling system (strip down the machine, clean all dust, reapply thermal paste) is £55. However I'm not sure if they'd do that if you've removed the optical drive. It's worth checking with them though, or maybe have it serviced at an Apple Repair Centre.

    Otherwise if you're fairly confident to reapply the thermal paste it may be worth looking into doing that.

    I know the Radeons on the 2011 MacBook Pros had documented issues with overheating and failing, though there doesn't seem to be a problem with the Radeons on the iMac. Please could you try game on it and advise what temperatures the GPU is running at? You can use Hardware Monitor ( to check this, though if you use a different application that's fine too.

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