PowerBook freezes when maximum RAM installed: Fix
Several readers have now reported an issue where various PowerBook G4 models exhibit repeated freezes when they contain the maximum amount of installed memory modules (RAM).
The issue is most prominent on PowerBook G4 15-inch 1.67 GHz models with the maximum amount allowed by two modules (usually 1.5 GB or 2 GB) of RAM.
There does not seem to be a common factor among users who are experiencing this issue, aside from having maximum installed RAM. It does not appear to make a difference which manufacturer the RAM comes from, nor does it appear that any specific system processes can reliably repeat the issue.
It appears that this issue can be solved by turning off the Nap function on the PowerBook G4's processor with the aid of Apple's CHUD Tools. [Turning off NAP has proven effective in previous troubleshooting issues, such elimination of a "chirping" noise generated by some Power Mac G5s.]
In order to perform this workaround, download and install the CHUD tools, then restart your system (as is required). Next, go to System Preferences and look for the "Processor" pane. Open it, and you will see an option called "Nap." Uncheck this option, then close System Preferences.
Note that your system may run slightly hotter when the Nap option is turned off, as these feature is designed to save energy and (in the process) keep the CPU somewhat cooler.
Feedback? Late-breakers@macfixit.com.
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same here, 2gb, no freezes
2 GB of Crucial memory here. This article is inaccurate and misleading.
Well, they don't say EVERY Powerbook G4 has this problem.
yeah i can read... its nice to know u can too...
My response wasn't to your post--it was to the one my post is attached to, in which the author stated "This article is inaccurate and misleading."
There are at least 2 misleading aspects:
1. As anyone knows, the maximum amount of RAM in these models is 2 GB, not
1.5 GB. This error casts doubt on the credibility of the entire article.
2. The advice about installing CHUD tools to turn off the nap function on the G4
seems overly complicated and frankly, not helpful. What average user is going to
do this? More importantly, if PB freezes are associated with RAM, the first thing
to try would be to install another RAM SIMM from the vendor, or another RAM
SIMM from another vendor.
You're right that the maximum amount of RAM that the PowerBook G4 15-inch 1.67 GHz model can hold is 2 gig (though I don't agree that this is "as anyone knows"), so MacFixit got this part wrong, but the MacFixit article begins by referring to "various PowerBook G4 models" since the Apple Discussions page about this problem that David Heintz refers to below (http://discussions.apple.com/thread.jspa?threadID=436503&start=0&tstart=0) has two people posting about earlier Powerbook G4 models who had the same problem and the same fix (AndersB has a 1.25 GHz 15" model, which he's put only 1.5 gig of RAM into, even though it can hold 2 gig, and Supars has an 867 MHz model, which holds a maximum of 1.152 gig if it's a 12 inch model, or 1.0 gig if it's a 15 inch model--he's not specific about this). Given this, it's possible that some other Powerbook G4 models could be affected too, so "various" is still a valid term. This could go all the way back to the first Powerbook G4, whose maximum RAM is one gig. Models between the original and the 1.67 GHz had different maximum RAM figures--about half could take 2 gig, and the rest could take only 1.25 gig. The "MacTracker" application is handy for this info.
The advice to install the CHUD tools isn't that complicated, and it is helpful since it apparently stops the problem for many, maybe most people experiencing this specific problem. It's hard to say what an average user is, but I'd guess that most users who just want the problem solved quickly would either figure out how to install CHUD, or get someone more knowledgeable than themselves to do it--after all, once CHUD is installed, all the user has to do is to open the Processor prefpane and click on a simple checkoff to turn off the Nap function. True, the better longterm solution would be to try different RAM, but this could mean going through several RAM vendors until you find one whose RAM boards don't have the problem--a RAM vendor can tell you till they're blue in the face that their RAM doesn't have this problem, but the proof is what happens when you install it. I've experienced various RAM vendor issues like this before, with various Mac models that I've worked on for various clients.
<p>Actually, this is a real issue, and I am the one who sent it to maxfixit:
http://discussions.apple.com/thread.jspa?
threadID=436503&start=0&tstart=0</p>
<p>It seems to be affecting the PB 15"HD machines that are maxed out to
2GB. It would be helpful if those who posted here having no problem confirm
their PB model, as most of these problems are with PB5,8.</p>
<p>Turning off the nap function is an easy workaround, but what is this
doing to the laptop? And hey -- it is new, isn't it?</p>
-David
I have a maxed out PB5,6 with no problems
GREAT HINT.
Just reduced my CPU usage on 17" 1.67 2GB PB to nil by comparison. Starts up
faster. This is wunderbar.
I have a 17'' G4 1.33GHz Powerbook that until recently ran on 512MB ram.
Recently I pulled out the original 512MB chip, and installed 2GB of ram. Ever
since the installation, I have had repeated screen freezes.
Extra details include that I always run my powerbook off the a/c adapter [not
the original OEM type as that failed the first year I had the powerbook, but
one that gave me no problems under the 512MB ram configuration.
I have observed that 99% of my freezes occur when the a/c plug gets moved
around in any way - especially if it happens to get pulled out even the
minutist fraction from being totally pushed in to it's proper slot.
Another detail is that I had to try 3 separte sets of 2 1GHz memory chips
before my powerbook finally recognized the new memory. I never could get
my powerbook to recognize any of the 1 GHz chips when leaving the original
512MB chip in the top slot and installing one of the 1 GHz chips in the lower
slot.
I will be trying the -NAP- fix suggested, but am also curious if there are
others with systems like mine who also have the freezes connected to the a/c
power cord wiggling around.
is gone.. superb!! :)
1.5 in for about 5 months and I have not had a single freeze or problem.
HD model with 2GB ram?
- by nprg May 31, 2006 3:33 PM PDT
- I've not had any freezing problems whatsoever with maxed out RAM; PB details are:
- Like this Reply to this comment
-
(18 Comments)Machine Name: PowerBook G4 15"
Machine Model: PowerBook5,8
CPU Type: PowerPC G4 (1.5)
Number Of CPUs: 1
CPU Speed: 1.67 GHz
L2 Cache (per CPU): 512 KB
Memory: 2 GB
Bus Speed: 167 MHz
Boot ROM Version: 4.9.6f0