Malcolm Herbert wrote: > I've recently re-discovered the CF disk that came with my net4801 and > was wondering what use it would be as a swap device ... I'm aware of > the fact that CF media doesn't last indefinately, but I'd be interested > in hearing whether others had tried this and how long it lasted before > giving problems ...
Assuming your wear leaveling algrithm works... with a very fast 4GB flash card. 30MB/s * 86400 = 2.592TB per day = 648 cycles 100,000 cycle rated flash / 648 cycles per day = 154 days of continious writing. Most flash components are slower than that. and of course the bigger they are the more area they have to use for wear leveling. > unfortunately swap problems are generally fatal, so I may just decide > to stick with swap on the attached HDD ... flash memory controllers generally implement ecc sufficient to repair multibit errors. it in not a panace and at the point where you start lossing whole blocks you have a problem (smart can tell you a bit about the flash if the controller implments it) but the products are becoming quite mature. I prefer not to built embedded systems that swap to flash but I'll do it in a pinch. If you're building a bunch of embedded systems, find an industrial flash manufacturer the makes their own controller firmware and have them validate their product for your workload. _______________________________________________ Soekris-tech mailing list [email protected] http://lists.soekris.com/mailman/listinfo/soekris-tech
