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SOLVED: iMac 27'' (Late 2009) Poor Performance and Flash Issues w/ SOLUTION

22646 Views 32 Replies Latest reply: Nov 7, 2009 7:09 AM by Reuben Feffer RSS
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Frederico Calculating status...
Currently Being Moderated
Oct 31, 2009 1:54 AM
I was able to cure all my performance issues by doing a low-level power/video/parameter reset (NVRAM/PRAM) to my iMac 27'' / 3.0Ghz / 4GB / ATi Radeon HD 4670 256MB

I had the following symptoms:

 Ridiculous boot time (5-6 minutes)
 Sluggish behavior in all window-based operations (hide/show/open apps; switch apps; open new windows, docs, etc.)
 Abhorrent Flash performance (even worse than usual for Flash)
 Xbench score = 124.22 (pathetic)

Steps to cure:

1) Shutdown iMac
2) Unplug power cord from back of iMac
3) Press and hold power button for 20 seconds
4) Restore power cord; power on iMac
5) Immediately on hearing Startup Chime, press and hold Command-Option-P-R keys (⌘⌥ P R)
6) Wait until you hear an additional four (4) chimes; the fourth (fifth) chime will (should) be louder and clearer
7) Release the keys and allow iMac to boot normally.
Note: This reboot may take up to two minutes, but subsequent reboots should be less than 30-45 seconds.

 Boot time 35 seconds
 super snappy app/window behavior (especially Parallels/Windows and Safari/Flash
 New Xbench Score = 286.24 (must admit I thought this would be higher)
 Super Happy owner of the hands-down, most kickass screen on the planet


Message was edited by: Frederico
Mac Pro Quad 2.8/6GB/ATi HD 2600 x 3/ 5 LCD Displays, Mac OS X (10.6.1), iMac 27'' / 3.0Ghz / 4GB / ATi Radeon HD 4670 256MB
  • sgginc Level 3 Level 3 (640 points)
    Just curious:

    Why 4 chimes?
    How is this different from 3, 2 or 1 chime?

    Thanks ... Ken
    MacBook Pro; Mac Pro 3.2, 8800GT, 16Gb; G5 Dual 2.5, Mac OS X (10.6.1), 30" and 23" ACD
  • Reuben Feffer Level 2 Level 2 (195 points)
    Frederico, what does this solution actually do? I mean, does it have an official name? What is it actually doing to the iMac?
    iMac (21.5-inch, Late 2009), 3.06GHz, 4GB RAM, 1TB Hard Drive, Mac OS X (10.6.1), 16GB iPhone 3GS, 40GB Apple TV
  • Bryan Lyle Level 1 Level 1 (35 points)
    These steps are resetting the PRAM and SMC. Would be interested to hear if this helps others as well.
    Mac Pro, Mac OS X (10.6.1)
  • John Keith5 Calculating status...
    This is basic Mac troubleshooting. Its always worth a try and if it fixes the issue then great! If you try this, it would be good to hear your outcome.
    Quad PM G5 2.5GHz, 23" Cinema HD Display, Mac OS X (10.5.8), 2.5GB, nVidia GeForce 7800GT, Airport, Bluetooth
  • Mitchell Davitte Level 1 Level 1 (0 points)
    Had my 27" for 6 hours. Loaded all my software and when I started to try and change font size started getting bad behavior. Not sure if this caused it but safari would not work and when I tried to reinstall safari it said it was not compatible with this version of os. Yes I downloaded the correct version of safari. Finally the solution was a complete reinstall of snow leopard from the install disc. Works great now. Is it possible the Chinese factory install of the OS is corrupt on 27" iMacs??
  • good sam Calculating status...
    has anybody tried this solution? is it a permanent fix, or does this problem persist?

    i've had this imac for 2 days and i can't begin to explain how disappointed i am. if this is a sign of things to come, i will undoubtedly return this computer.
    iMac 27", Mac OS X (10.6.1)
  • Diamond White Level 1 Level 1 (0 points)
    I've been running for around 1 hour since trying this solution, seems to be OK. Lets hope it lasts. Thanks for the tip.
    2.4 GHz iMac 24" Aluminum, 17" G4 PowerBook, 3.06 21.5" imac, Mac OS X (10.6.1)
  • Dah•veed Level 7 Level 7 (29,505 points)
    Frederico please share where you got this information to follow these steps?

    I ask because they are not the steps for either a conventional SMC reset on an Intel iMac, nor a conventional PRAM/NVRAM reset on an Intel iMac.

    '09 Mac mini 2GB RAM - 250GB miniStack v3, Mac OS X (10.6.1), 17" iMac CD 2GB RAM - Nano (3G) 8GB - Happily using Macs since 1984!
  • good sam Level 1 Level 1 (0 points)
    this process does not work for me at all. i'm only getting to the second chime... what gives?
    iMac 27", Mac OS X (10.6.1)
  • FaZe Calculating status...
    I also only get a second chime.
    iMac 27", Mac OS X (10.6.1)
  • Michael Lafferty Level 6 Level 6 (16,080 points)
    They are roughly analogous to the instructions outlined in the Technician Guide—formerly called the Service Manual—for the iMac 27 inch (Late 2009) product family, and are similar generally to those in an applicable technical note for iMac and Mac mini products which use an intel processor.

    The actual instructions from the guide are these for resetting Parameter RAM:

    • shut down the computer.
    • find the ⌘, ⌥, P, and R keys. If the keyboard does not have an ⌥ (option) key, use the Alt key.
    • pres and hold the power button.
    • immediately press and hold ⌘-⌥-P-R keys combination. You must do so before the gray screen appears.
    • continue to press these keys until the computer restarts, and you hear the startup chime a second
    • release the keys

    And these, for resetting the System Management Controller:

    • from  menu, choose Shut Down or hold the power button for ten or so seconds until the unit powers off.
    • unplug all cables from computer including power cord
    • wait at least 15 seconds: SMC reset occurs automatically once an iMac has been unplugged from AC power source for several seconds.
    • plug power cord back in, making sure power button is not being pressed
    • press power button on back to start up computer

    I and most technicians I know have always waited for four startup tones to insure a proper PRAM reset: this goes back to the days of OS 6. As you can see, his instruction steps to do both in a single set are a hybrid of Apple's instruction set to achieve each reset.
    PowerBook G4 12 inch 1.5 GHz 1280 meg 80 gig SuperDrive, Mac OS X (10.4.11), coupled with a UMA-capable Nokia 7510 Supernova and T-Mobile HotSpot™ @Home
  • Dah•veed Level 7 Level 7 (29,505 points)
    As you can see, his instruction steps to do both in a single set are a hybrid of Apple's instruction set to achieve each reset.

    It is and it is not, which is why I am curious where he got these steps. What you quote from the Tech Manuals available to you are the same instructions available to all of us in the Apple Knowledge Base. And if you read the instructions in the KB you will see that Apple went out of their way to make sure folks who used to have PPC iMacs did not bring old habits of pressing the Power button with them to the Intel iMacs. And yet his step 3 involves a press & hold for the power button 20 seconds.

    I have never seen an instruction to wait until one startup chime before pressing the key combo for the PRAM/NVRAM rest. And there are plenty of conversations around the web regarding bad experiences of holding the reset combo beyond two chimes. We also now have two folks in this thread reporting that their new iMacs will not do more than two chimes!

    So I am curious if he made this up, read it somewhere or has access to Tech Manuals most of us do not have.

    '09 Mac mini 2GB RAM - 250GB miniStack v3, Mac OS X (10.6.1), 17" iMac CD 2GB RAM - Nano (3G) 8GB - Happily using Macs since 1984!
  • Kenichi Watanabe Level 7 Level 7 (29,985 points)
    Keep the four PRAM reset keys held down until you hear the chime repeat as many time as you want them to repeat. When you are tired of listening to the chime sound every five or so seconds, let go of the keys and the iMac will proceed with the startup.
    Various including Intel iMac, Power Mac G5, Pismo w/G4, Power Mac 8100 w/G3, Mac OS X (10.6.1), also Mac OS X 10.4.11, Mac OS X 10.3.9, and Mac OS 9.x
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