On Thursday 11 October 2012 05:37:26 pm Wayne Merricks wrote: > USB pen drives also generally have quite low write wear rates before the > flash dies, its not a problem I've ever noticed over the years but I suppose > if there is constant writes to the drive you might eventually burn out part > of it. > > Having said that its probably not much less reliable than normal drives. >
Modern flash memory is typically good for 100K or so erase-write cycles. Some of the newer flash are claiming 1M cycles, so yes, at some point they will start reporting errors as the ROM wears out, but the real question ( to which you allude ) is how many erase-write cycles will you be subjecting it to over its expected life ? ( erase is much harder on the ROM than write ) In my experience as a data recovery guy, hard disks fail mostly due to mechanical reasons. Bearing failure in Western Digital, head crashes in Seagate, they all have their typical failure modes. These are functions of mechanical stress. Flash doesn't suffer mechanical stresses, but the medium does "wear" with number of cycles. The controller on solid state drives tends to use the memory much like a conventional hard drive, where the data isn't erased. The sectors are merely marked "available" and sit dormant until needed, so even though a particular block ( and flash blocks are much larger. That's how they get speed over EEPROM ) has its wear limits, the controller by using other blocks can attempt to minimize wear on individual blocks, so a solid state "hard drive" can easily last as long as spinning platters. Longer, if the data on it is only a fraction of its capacity. -- Cowboy http://cowboy.cwf1.com There is a theory which states that if ever anyone discovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another theory which states that this has already happened. -- Douglas Adams, "The Hitch Hiker's Guide to the Galaxy" _______________________________________________ Rivendell-dev mailing list [email protected] http://lists.rivendellaudio.org/mailman/listinfo/rivendell-dev
