On Saturday, April 27, 2002, at 11:55 PM, munker wrote: > A number of years back IBM did some research into the cause of memory > errors in computers. > > Their findings were that cosmic rays were the principle cause. > > It seems that cosmic rays striking the transistors in the memory chip > can > cause one or more of the transistors to switch high. > > To prove it they moved their test computers 50 feet underground and over > the next 6 month period found that all memory errors ceased. > > With new programs and operating systems requiring more memory are we as > computer users looking at necessarily less reliability and stability? > > I mean the more transistors there are then the more of them that are > going > to be flipped high by cosmic rays. Also with manufacturers going to ever > higher density memory chips the greater the chance that the same cosmic > ray > will flip more transistors than if the chip was a low density device.
Their research showed that you should expect one error per month, caused by cosmic rays, per 256MB RAM. <http://www.eetimes.com/news/98/1012news/ibm.html> <http://www.research.ibm.com/journal/rd/401/ogorman.html> At one failure per month per 256MB, this is largely a non-issue for end users. It's a big deal, however, to servers and server farms that employ "big iron"; that is, servers with multiples of Gigabytes of RAM. > (If you drop a bomb on a high density population centre like a densely > crowded city you will wipe out more people than if you dropped the same > bomb in a rural area.) > > So my question is could putting more memory in your iMac actually make > it > less stable? Technically? Yes. Realistically, though, this study has little impact on end users. Even at 1GB RAM, cosmic rays would only account for one crash per week at most. I'm at mean sea level (well, a few feet above), and with 512MB RAM, I only crash when -I- cause the crash. -- 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! | SPECIAL LIST PRICES - Apple iMac CDROMs from $79.99, iMac DVD CDROMs from $99.99 3 port USB Hub $14.99, 40GB Hard Drive Upgrades $119 <mailto:[EMAIL PROTECTED]> Support Low End Mac <http://lowendmac.com/lists/support.html> iMac List info: <http://lowendmac.com/imac/list.shtml> Send list messages to: <mailto:[EMAIL PROTECTED]> To unsubscribe, email: <mailto:[EMAIL PROTECTED]> For digest mode, email: <mailto:[EMAIL PROTECTED]> Subscription questions: <mailto:[EMAIL PROTECTED]> Archive: <http://www.mail-archive.com/imac-list%40mail.maclaunch.com/> Using a Mac? Free email & more at Applelinks! http://www.applelinks.com
