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

Question

Level 1

12 points

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

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.

Results:
 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
HTH

Frederico

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

Posted on Oct 31, 2009 1:50 AM

Reply

Answer 1

Top-ranking reply

Michael Lafferty

Level 6

16,085 points

Oct 31, 2009 11:10 PM in response to Dah•veed

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.

Reply

Answer 2

Oct 31, 2009 4:31 AM in response to Frederico

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??

Reply

Answer 3

good sam

Level 1

8 points

Oct 31, 2009 11:15 AM in response to Frederico

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.

Reply

Answer 4

Dah•veed

Level 9

65,461 points

Oct 31, 2009 2:15 PM in response to Frederico

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.

Dah•veed

Reply

Answer 5

Dah•veed

Level 9

65,461 points

Oct 31, 2009 11:29 PM in response to Michael Lafferty

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.

Dah•veed

Reply

Answer 6

Oct 31, 2009 11:30 PM in response to FaZe

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.

Reply

Answer 7

myhighway

Level 5

7,270 points

Nov 1, 2009 12:46 AM in response to Mitchell Davitte

+Is it possible the Chinese factory install of the OS is corrupt on 27" iMacs??+

Yes, definitely. A bad factory install has happened before, and will happen again.

In fact, although it was a different scenario, something similar happened within the past few years during an iMac introduction (I've lost track of exact time frame) - Apple had to ship out a replacement "Install Disc 1" to a substantial number of new owners. I'm certain those threads are still available, if anyone cares to search.

Reply

Answer 8

myhighway

Level 5

7,270 points

Nov 1, 2009 12:57 AM in response to good sam

+i'm only getting to the second chime... what gives?+

The key diagnostic for whether or not the reset has occurred is being able to notice the reset of the sound level to its default level. Unfortunately, such a difference can only be noticed by those who have previously adjusted their system sound level from its default position since their initial startup - I'm not sure how pervasive this is, although I'm sure I always adjust my sound preference as one of the group of about six preference settings I immediately change, even before proceeding with Software Updates.

Reply

Answer 9

Nov 1, 2009 6:44 AM in response to Sinan Uyar

I've tried the reset, and got all four chimes - no luck! After about 30 mins of iTunes music playing and a bit of Photoshop work, one of the cores acted up again, and I had to restart the computer.

The first thing I did, when I got my iMac 27" was to insert my retail Snow Leopard cd, I purchased back when it was released. I then updated it by Software Update.

I've had this iMac for 6 days now, and these are the problems I've encountered:

Flickering display
Topbar moved 2/3 of the screen down(2 times)
And major slowdowns - and not only with Flash but also with iTunes(When playing music)

The one things that goes again, is that is seems to come every time I use the graphic-card hard - like using Photoshop. But this might just be coincidence.

I've run an extended hardware test(Disc 2 Holding D) took about an hour, and returned no errors.

Hopes this answers some questions people have out there.

Reply

Answer 10

blort

Level 1

0 points

Nov 1, 2009 10:24 AM in response to jonashh_dk

Hi!

I've done some tests and it looks like either the wireless card is at fault, or the wireless driver.

If you're experiencing CPU spikes on one core after using your computer for a bit, try turning off AirPort, and then turning it back on. As soon as you turn off AirPort, the affected core goes back to normal.

A few things to think about: Your 27" iMac works _just fine_ until something happens in either the wireless card or in AirPort, at which point things slow down. This means that the hardware is capable of functioning properly, which means that it's most likely a driver issue that will be patched up soon.

Try running your iMac with AirPort turned off for a few hours, and see what happens.

Hope this helps =)

Reply

Answer 11

ai31

Level 1

0 points

Nov 1, 2009 11:07 AM in response to blort

Yes it definitely appears to have to do with AirPort. Turning it off and on does fix the Flash Player problem immediately. The CPU activity goes back to normal and all video works properly and the computer stops its performance issues. Now if we can get apple to release a fix for the problem it would be nice.

Reply

Answer 12

Nov 2, 2009 9:40 AM in response to myhighway

From what I have seen the following step will fix this issue temporarily - Flash video will play normally if you click on the AirPort menu extra and let it scan for networks.

This works for about 20 minutes to an hour. Once the issue starts again, repeat the scan for networks.

Best of luck. Let me hear how this works out for you.

Reply

Answer 13

blort

Level 1

0 points

Nov 2, 2009 2:52 PM in response to laundry bleach

It looks like it may have something to do with the way AirPort uses certain routers for DNS. I changed my AirPort DNS settings to use OpenDNS's IP addresses (those are available at www.opendns.com), and the problem went away completely.

Let me know if this works for you.

Reply

Answer 14

ktolani

Level 1

0 points

Nov 2, 2009 10:40 PM in response to GizaDog

how do u do tht?? do u just type "openDNS" on the dns box instead of 192.168.1.1? i mean im kinda new at these things. so i would appriciate if you could guide me.
thx

Message was edited by: ktolani

Reply

Answer 15

Nov 3, 2009 8:39 AM in response to GizaDog

I can also confirm that changing to OpenDNS won't fix anything, as I am always using OpenDNS, as I live in a country(Denmark) where the music/movie industry obviously has to much power, or has bribed the danish court.

Reply