Update
I've now had my Dual 2.5 GHz G5 since 8/12 (almost a month now! it's hard to believe...). Aside from a weird series of kernel panics (now solved; see below) the machine has been ROCK-SOLID. Mine is quiet, does not experience any abnormal temperature spikes/scrolling screen waviness/fan revving, and in generally is perfectly well-behaved. It's also VERY FASY, and well worth the wait! Too all of you still waiting: you will be THRILLED with the performance once you get yours; it really is a LOT faster than I expected.
Kernel Panic Information
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I've had four kernel panics since receiving my new Dual 2.5 Ghz G5 on 8/12... I only had four KPs in the entire two years I used my Dual 1.0 GHz "MDD" Power Mac G4!
The first G5 KP was on 8/20 while playing UT2004 with a huge third-party VCTF map. This was surprising, but didn't overly concern me.
The next THREE have been in the last two days... The second was at about 1:00 AM on 8/30, while the machine was idling (I was asleep). The fan noise woke me up (I'm a light sleeper) and I restarted it. The third was at about 3:00 AM on 8/30, again while the machine was idling (I was asleep). I powered if off until the morning, when I uninstalled the only real software I'd installed for the last few days: TechTool Pro 4.0.2 (updated to 4.0.3). I though TTP4 was probably the problem.
The G5 was stable until this morning (around 9:30AM on 8/31), when it KP'd again when I was renaming a file in the Finder... Odd! The last two KPs have the same basic panic.log entry. I was monitoring temperature, fans, voltages, and the like during the last KP, and everything looked perfectly normal.
After reading every 2.5 GHz KP entry on every Mac forum I could find, I began to suspect some sort of interaction with Marcel Bresink's excellent Hardware Monitor utility. I sent him an e-mail with my suspicions and asked him if could look into it, which he did with astonishing speed.
Marcel Bresink isolated a "memory management problem in the way the kernel driver for the Apple Fan Controller Unit interacts with the cooling control of Power Macintosh G5 systems. This error is detected by the kernel which in turn halts the system with a Kernel Panic message. The problem is limited to Power Macintosh G5 systems, 2003 or 2004 models, running Mac OS X 10.3.3, 10.3.4, or 10.3.5. Other OS versions prior to 10.3.3 are not affected".
These kernel panics can apparently occur without Hardware Monitor running, since the bug is apparently in Apple's Fan Controller Unit driver, but Hardware Monitor uses these driver routines and thus inadvertently increases the frequency of the kernel panics on affected systems. Since this is a problem in the Apple Fan Controller Unit driver, he will be releasing a revised version of Hardware Monitor that temporarily disables the feature to display fan control readouts until Apple has fixed the problem. He has reported the problem to Apple, so hopefully they will release a fix quickly! Marcel asked me to note that his analysis is preliminary.
I want to thank Marcel for his extremely quick and thorough testing and analysis of this issue. Marcel also writes the excellent TinkerTool freeware, and his web site is
here.