AllusMatt

Q: Why is my brand-new 16GB, i7 21" iMac running so so slow?

I have recently purchased a 21" iMac with the following Spec;

 

21.5" Retina 4K 2015 iMac

3.3GHz Intel Core i7

16GB 1867 MHz DDR3

Intel Iris Pro Graphics 6200 1536 MB

 

Ever since day one it has been running remarkably slow. Even when opening things such as finder and system preferences.

 

I currently own a macbook pro as well which runs 5 times faster than my iMac.

 

Do you have any suggestions of why this might be?

 

Thanks in Advance

iMac (Retina 4K, 21.5-inch, Late 2015), OS X El Capitan (10.11.5)

Posted on Jul 22, 2016 2:55 AM

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Q: Why is my brand-new 16GB, i7 21" iMac running so so slow?

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  • Helpful answers

  • by seventy one,

    seventy one seventy one Jul 22, 2016 3:09 AM in response to AllusMatt
    Level 6 (15,098 points)
    Peripherals
    Jul 22, 2016 3:09 AM in response to AllusMatt

    Where did you buy it from?

    Have you registered it.   (It is covered by a twelve month guarantee).

    Do you have an Apple store nearby?

  • by Mike Sombrio,

    Mike Sombrio Mike Sombrio Jul 22, 2016 3:21 AM in response to AllusMatt
    Level 6 (17,194 points)
    Apple Watch
    Jul 22, 2016 3:21 AM in response to AllusMatt

    It's possible that you've installed some poorly written or incompatible software. If you'd run and post an EtreCheck report we'd get a better idea about what may be going on http://etrecheck.com/

  • by Linc Davis,

    Linc Davis Linc Davis Jul 22, 2016 7:40 AM in response to AllusMatt
    Level 10 (207,926 points)
    Applications
    Jul 22, 2016 7:40 AM in response to AllusMatt

    The warranty entitles you to complimentary phone support for the first 90 days of ownership.

    If you bought the product in the U.S. directly from Apple (not from a reseller), you have 14 days from the date of delivery in which to exchange or return it for a refund. In other countries, the return policy may be different. If you bought from a reseller, its return policy applies.

  • by AllusMatt,

    AllusMatt AllusMatt Jul 22, 2016 11:46 AM in response to seventy one
    Level 1 (8 points)
    Desktops
    Jul 22, 2016 11:46 AM in response to seventy one

    I purchased this from the apple store. Should i get in touch with them?

  • by AllusMatt,

    AllusMatt AllusMatt Jul 22, 2016 11:48 AM in response to Mike Sombrio
    Level 1 (8 points)
    Desktops
    Jul 22, 2016 11:48 AM in response to Mike Sombrio

    Hi, the only thing I run on it is Adobe Creative Cloud. Which I also run on my macbook pro with no issues what so ever.

  • by babowa,

    babowa babowa Jul 22, 2016 12:58 PM in response to AllusMatt
    Level 7 (31,893 points)
    iPad
    Jul 22, 2016 12:58 PM in response to AllusMatt

    In order to compare, what hard drive(s) are in your iMac and your MBP? Are they the same 5400 rpm or does one have an SSD or ???

  • by MichelPM,Helpful

    MichelPM MichelPM Jul 26, 2016 3:03 AM in response to AllusMatt
    Level 6 (13,653 points)
    iPad
    Jul 26, 2016 3:03 AM in response to AllusMatt

    If your iMac has either a the straight AND slower laptop standard 5400 RPM hard drive or even fusion drive, the hard drive on fusion drives, in the 21 inch screen models are even the slower 5400 RPM drives which will make your iMac still slower where access to the hard drive portion of the fusion drive is needed.

    The straight up SSD in the 21 inch screen iMac is the way to go in these new 21 inch screen iMac models for the fastest data in/out throughput.      

  • by AllusMatt,

    AllusMatt AllusMatt Jul 26, 2016 3:08 AM in response to babowa
    Level 1 (8 points)
    Desktops
    Jul 26, 2016 3:08 AM in response to babowa

    Hi, they both have 5400rpm storage. Is this something that will affect the speed?

  • by MichelPM,

    MichelPM MichelPM Jul 26, 2016 3:59 AM in response to AllusMatt
    Level 6 (13,653 points)
    iPad
    Jul 26, 2016 3:59 AM in response to AllusMatt

    Yes,

    The slower hard drive is going to negatively impact iMac performance.

    That and, I beleive, that Intel Iris Pro graphics are integrated GPUs and not discreet, meaning the GPUs in the 21 inch screen models get their VRAM from the total physical RAM installed in these smaller screen iMacs.

    The 21 inch screen iMacs do not have GPUs with discreet, independent GPUs with their own dedicated VRAM.

    Some of the 16 GBs of pysical RAM is going toward supplying VRAM for the GPU.

    So, if you have an app that is heavy with GPU tasks, the GPU is going to take as much of the available physical RAM as  that application needs to process video/graphics oriented tasks.

     

    So, if your iMac has 16 GBs of RAM, the OS uses between 6-8 GBs of RAM, Video takes for its use bewteen, say, 256 MB-4 GBs of RAM, this may only leave available between 4-6 GBs of RAM for running applications.

  • by babowa,

    babowa babowa Jul 26, 2016 8:08 AM in response to AllusMatt
    Level 7 (31,893 points)
    iPad
    Jul 26, 2016 8:08 AM in response to AllusMatt

    I had a Mini with 5400 rpm drive and I sold it three months later at a loss; my current MBP came with one as well, but I immediately upgraded that to an SSD instead. I found them to be unacceptably slow.

     

    Hard drives are more than "storage" - the regular spinning drives rotate like a CD or DVD while they are being written to or read from. The OS processes everything you do so it either reads/writes to the hard drive constantly. Spinning at 5400 rpm is about 33% slower than the hard drives in 27" iMacs which are 7200 rpm. That is the slowest I'll consider if I cannot afford an SSD.