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Level 1

8 points

Macbook Pro (late 2008) with 8GB ram sporadic freezing / hanging

Hi,

Last year, I was running Lion on my late 2008 MBP with 4GB ram with no problems. Whilst 4GB is the maximum officially supported for my machine, forum posts suggested that some people had no issues running it with 8GB.

I went for the upgrade and everything was fine, with no hanging - 8GB on Lion on my machine seemed to work fine.

When I then upgraded to 10.7.2 I had a separate issue (to do with an old install of PGP) which meant I had to do a fresh install of Lion from scratch and then restore from Time Machine to get it back working. Ever since I did this, I have experienced odd behaviour, notably:-

Machine has a tendency to hang / freeze every now and then for up to 10 secs and sometimes with the spinning wheel and sometimes also requiring a hard reset
Any mounted drives in Finder (dropbox, Truecrypt) sometimes don't come up at all, with the Finder progress wheel spinning in the bottom status bar of the window, and only a "Relaunch Finder" resolves this and allows me to access the mounted drive.
Machine seems a little sluggish despite me keeping on top of maintenance activities for my machine (as I used to for SL and Lion when I first installed)

I was wondering whether there was something whereby Lion would work fine had it been installed whilst the machine had the officially supported 4GB (and then later upgraded to 8GB) as opposed to installed on a machine with 8GB (which only officially supported 4GB) at the time of install. As above, everything was working happily with the 8GB until I had to do a completel refresh from scratch.

Has anyone else had experiences of anything similar and can shed some light? I am considering refreshing and restoring from time machine again with just 4GB in the machine and then putting the extra 4GB back in after the restore, but don't want to do this unless there is any evidence to suggest this will address some/all of the issues I'm experiencing.

Thanks in advance.

MacBook Pro (15-inch Late 2008), Mac OS X (10.7.2)

Posted on Jan 31, 2012 4:06 AM

Best reply

wjosten

Level 10

95,321 points

Posted on Jan 31, 2012 4:12 AM

AFAIK, you had to have the proper Boot ROM Version to get the 8GB's to work...you couldn't just slap 8GB's in. Did you do/verify this before upgrading to 8GB's? Details here:

http://blog.macsales.com/9102-secret-firmware-lets-late-08-macbooks-use-8gb

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20 replies

Mar 21, 2013 7:45 AM in response to jlaverick2

On another note...when running Activity Monitor with Snow Leopard, I was showing 7.75gb RAM. After the upgrade to Mountain Lion, I showed all 8gb with Activity Monitor

tpark

Level 1

0 points

Apr 3, 2013 9:10 AM in response to gggtraveller

Hi,

1) I have had problems with the machine running 1333 mhz memory - the machine would sporadically hang, but it would mostly work OK. The machine has been fine since I put some 1066 memory in it. I replaced the drive with a 750gb WD scorpio black, and the system is still stable. It may be that the 1333 memory cannot reliably operate at the slower clock speed that the late 2008 aluminium macbook provides, but I can't be absolutely certain - I just know that it works correctly again.

The computer crashed running either OSX lion or Windows 7 so I think it was an actual hardware problem, not an issue with the operating system.

The memory that didn't work is labeled CMS04GX3M1A1333C9

The memory that works is labeled CMSA8GX3M2A1066C7

basilmir

Level 1

80 points

Apr 4, 2013 2:01 PM in response to tpark

It's apple hardware in general, it does not force the lower speed. It just presumes everything is in the required spec.

You have to manually choose and put in per spec memory.

Just read the apple spec and you'll be ok.

In case older spec memory is hard to find you have to flash higher speed ram to cap it to the lower speed using software like Thaiphoon Burner and a compatible mainboard on a pc.

The guide here is not for the faint of heart but it is possible to flash 1333 cas 9 to 1066 cas 7 and use them nicely.

http://tylermilner.com/?p=342

basilmir

Level 1

80 points

Apr 4, 2013 2:05 PM in response to tpark

The problem is the integrated video card that uses shared ram as video memory. If the ram is higher spec it overclocks itself. If you check the logs you'll see nvidia driver crashing every time.

Using the late 2008 macbook in performance mode with the non shared 9600gt leads to greater stability but still crashes sometimes.

May 31, 2013 2:47 PM in response to basilmir

I think your close to the cause here. I also have the 8GB Ram at 1067 DDR3 according to System Profile.. When using higher performance, 9600M GT enabled, high CPU usage causes a full lock up, requiring hard reboot. Sometimes just using the Mac all day and then doing a large network or FireWire file transfer will cause a lockup as soon as you switch between apps or even watch a news video from websites.

Switching back to 9600M keeps it relatively stable. Even when doing processor intensive work.

I have experimented in using the original 4GB RAM configuration and clean install of 10.8, with similar results. Locks up with 9600M GT enabled. Relatively stable with 9600M enabled.

I haven't tried and simply cannot go back to the original shipping OS to do further testing. I do not have an extra machine to use for work when traveling. So I cannot confirm if its OS specific with my current memory configuration.

On a side note, the 9600M performs 33% faster using DDR3 memory, rather than DDR2. So for the most part I keep the MBP on 9600M Better Battry Life setting.

Macbook Pro (late 2008) with 8GB ram sporadic freezing / hanging