All, I just came across this issue on Macintouch.com. It appears that you can have good luck with certain RAM running OS 9, but install OS X , Jaguar, and the same RAM can now cause kernal panics, startup problems of various sorts, and what appears to be many of the bugs associated with Jaguar installs. Unfortunately there doesn't yet appear to be a test to check your RAM, other than to perform some troubleshooting by removing RAM and checking stability. So, I've copied a couple of the reader reports here. For anyone interested in further discussions, go to http://www.macintouch.com/badram01.htmland . This is really interesting.
Jerry ""following copied from macintouch.com ... The Problem It has become clear that Apple's memory tests, which slow down the startup process, are not only ineffective, they're actually misleading. We haven't seen many examples of these tests identifying serious RAM problems (only the most extreme cases), but we're seeing a number of examples of bad memory passing all Apple's tests while it ruins a system's reliability. It took us weeks to debug one of these problems on a new Power Mac G4/800 running Mac OS 9. The bad memory card corrupted the hard drive, as well as causing frequent crashes. We've already had reports of similar problems in Mac OS X, which can fail on memory that worked successfully with Mac OS 9. This problem is critical. It can stealthily and randomly destroy your files and your work. -Ric Ford ---------------------------------------------------------------------------- ---- A Query Date: Mon, 11 Nov 2002 01:57:21 -0500 From: Seth Ober Subject: One (possibly widespread?) cause of 10.2 kernel panics, crashes & VPC problems. I had a very stable system running Jaguar, with an occasional crash or kernel panic when pushed hard (Virtual PC and/or 10+ simultaneous applications). The entire system, including RAM, passed all AppleCare diagnostics and the tests on the diagnostics CD that came with the Mac. I had run the diagnostics a number of times on various occasions. I accepted the crashes and kernel panics as normal--I saw similar reports from others on the Connectix forums and the crashes were sometimes a week or more apart if I didn't run Virtual PC... Then, I downloaded the Otto Matic demo (from Apple's site) and tried playing it. It crashed consistently after 10-15 minutes. I decided to boot up in MacOS 9 to see if that would make a difference. The game consistently crashed within 2-3 minutes. After much experimenting, I tracked the problem down to a bad 512meg RAM module. When I tried that RAM alone or with other modules, the game consistently crashed the system after 2-3 minutes in OS 9 (and intermittenly in Jaguar). By removing or replacing the module, the game worked flawlessly. Since replacing the RAM, not only does the game work, but my system is now ROCK solid. Sure, an app crashes occasionally, but it has NEVER brought down the whole Jaguar system since I replaced the RAM, and I haven't had any more kernel panics at all, even when I've run dozens of applications at a time (including Virtual PC running multiple Windows XP sessions simultaneously--impossible with the flaky RAM). The occasional crashes that I had accepted as rare enough to be 'acceptable' and normal were actually a symptom of bad RAM. I don't think that the details about my system matter--the two morals of the story are simple: 1) If you're having ANY kernel panics or intermittent system crashes/freezes in Jaguar, try removing/replacing RAM even if it has passed diagnostics. If you don't have spare RAM to test with, try playing the free demo of Otto Matic from Apple's web site, especially under MacOS 9. That was the most reliable "Memory Test" I've found! 2) There is a definite need for a more thorough RAM test for Macs. --Seth Ober, thankful that my RAM vendor exchanged the RAM despite the diagnostic tests saying it was fine. P.S. I saw several reports of problems with Windows XP on Virtual PC that were similar to problems I had with it--problems that disappeared after I replaced the RAM. Flaky RAM may be a very widespread problem! Also, while testing, I found that Bejeweled (free from Apple with .mac membership) and the free demo of Bugdom 2 also crashed the system a lot with the bad module in place, but not as consistently as Otto Matic. Those games now run flawlessly, too. "" -- The iMac List is sponsored by <http://lowendmac.com/> and... Small Dog Electronics http://www.smalldog.com | Refurbished Drives | - Epson Stylus Color 580 Printers - new at $69 | & CDRWs on Sale! | Support Low End Mac <http://lowendmac.com/lists/support.html> iMac List info: <http://lowendmac.com/imac/list.shtml> --> AOL users, remove "mailto:"; Send list messages to: <mailto:imac-list@;mail.maclaunch.com> To unsubscribe, email: <mailto:imac-list-off@;mail.maclaunch.com> For digest mode, email: <mailto:imac-list-digest@;mail.maclaunch.com> Subscription questions: <mailto:listmom@;lemlists.com> Archive: <http://www.mail-archive.com/imac-list%40mail.maclaunch.com/> --------------------------------------------------------------- >The Think Different Store http://www.ThinkDifferentStore.com ---------------------------------------------------------------
