J. Burton

Q: Why does my iMac boot slower after upgrading RAM?

I recently upgraded the RAM in my late-2012 27" iMac from 8 GB to 16 GB using http://eshop.macsales.com/item/Other%20World%20Computing/1600DDR3S08S/ from macsales.com. The specs for the RAM are (for those of you who don't want to click an embedded link):

 

  • Technology: DDR3L SO-DIMM
  • Density: 4GB (4096MB) per module
  • RoHS: Yes
  • Pin Count: 204-pin
  • Op. Temp.: 0C to +85C
  • Data Rate: DDR3L-1600
  • Speed: PC3-12800
  • CL: 11
  • Cycle Time: 1.875ns
  • Voltage: 1.35V
  • ECC: Non ECC
  • Module Ranks: Dual Rank
  • Register: Non Parity

 

This appears to be the correct RAM and this is what macsales.com recommended after I checked the model number for my iMac (13,2).

 

However... Ever since I installed the new RAM, my iMac has booted noticeably slower. It's fast once it gets going, but getting to the login screen takes quite a bit of time (much more time than I remember with just 8 GB). There is no compression running VMWare which is the biggest reason for upgrading the memory. I mean, this iMac is fast - once it's booted.

 

Just for giggles, I booted in Safe Mode and repaired the hard disk. I rebooted and tested all the hardware using the hardware test. I have reset the NVRAM and it still boots slow. I'll time it using the standard 8 GB RAM and compare it to the 16 GB boot, but I mean it's three or four times slower. Where I could turn it on and get to the login screen before I could leave the room to I can go to the bathroom and come back before it's at the login screen.

 

Is there something else I can try or something I missed?

 

Thanks.

iMac, OS X Yosemite (10.10.3)

Posted on Jun 25, 2015 3:34 PM

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Q: Why does my iMac boot slower after upgrading RAM?

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  • Helpful answers

  • by Kappy,

    Kappy Kappy Jun 25, 2015 3:50 PM in response to J. Burton
    Level 10 (271,328 points)
    Desktops
    Jun 25, 2015 3:50 PM in response to J. Burton

    This may be because the system needed to modify a VM file as well as having twice as much RAM to verify during startup. Might I suggest you try a second or even third startup to see if that changes anything.

  • by babowa,

    babowa babowa Jun 25, 2015 3:53 PM in response to J. Burton
    Level 7 (32,103 points)
    iPad
    Jun 25, 2015 3:53 PM in response to J. Burton

    Well, it appears you have the correct spec RAM; I've always purchased RAM from OWC - only had a problem once and they sent out a free replacement immediately.

     

    Did you make sure it is seated correctly? And it is recognized by the system? Did you try to swap the RAM putting the new modules in slots 1 and 3 and putting the "old" RAM in 2 and 4 (from the top as it is facing you)? If that is ok, then we can rule out a problem with the slots. Other than those thoughts, I really have no answer - the only thing I can think of to suggest is to call their customer service and ask them if they have any ideas.

  • by J. Burton,

    J. Burton J. Burton Jun 25, 2015 5:04 PM in response to J. Burton
    Level 1 (0 points)
    Jun 25, 2015 5:04 PM in response to J. Burton

    Kappy and babowa,

     

    Thanks. Your help got me thinking about some troubleshooting I had overlooked. Nothing else changed with my computer - just the RAM. However, I've been a technician long enough to know that there can be other problems.

     

    I did not exaggerate about the three to four times slower. As a matter of fact, it was almost five times slower (1 min / 48 sec).

     

    I disconnected all of my external devices and left *just* the keyboard, mouse, and LAN connection. Boot time was 22 seconds.

     

    I added one thing back at a time and rebooted. I have a USB3 hub, an external sound card, my Lightning cable for my iPad / iPhone, a printer, and my external Time Machine hard drive. For almost all the devices, my boot time was from 22 to 24 seconds until I added my printer. When I added my printer back, it took 1 min / 51 seconds to boot. I had not noticed it until I saw the time that it appears my printer stopped "communicating" with my computer when I boot.

     

    The culprit is the printer, not the RAM it's just the printer chose to start acting up around the same time I added the RAM.

     

    Thanks for getting my mind thinking.

  • by cdhw,

    cdhw cdhw Jun 25, 2015 5:06 PM in response to J. Burton
    Level 4 (2,668 points)
    Servers Enterprise
    Jun 25, 2015 5:06 PM in response to J. Burton

    Try installing just the new 8GB, time, then try just the original and time again.

     

    C.

  • by J. Burton,

    J. Burton J. Burton Jun 25, 2015 5:25 PM in response to Kappy
    Level 1 (0 points)
    Jun 25, 2015 5:25 PM in response to Kappy

    Thank you, Kappy. That was it. I am saving the links.