Thumb Drive Life Cycle

May 24, 2007 8:29 AM

Thumb Drive Life Cycle

Wikipedia says USB flash drive media lasts for unlimited read cycles and "several hundred thousand" write cycles. http://en.wikipedia.org/wiki/USB_flash_drive

I've seen estimates ranging from 100,000 for older ones to 1,000,000 for newer ones.

This seems large, but at least the FAT gets rewritten constantly. I run Portable Firefox on my thumb drive, and it flashes all time time. Firefox also seems to be slowing down.

Am I reaching the end? If so, which brands have the 1,000,000 write media for when I replace my current drive?

posted by KRS to Computers & Internet (2 answers total)

There is some intelligence in the flash drive to avoid 'dead' sectors. The slow down is probably related to that (as you suspected). The FAT table as you said gets re-written constantly (any time you move or create a file), but when the location on the physical chip gets burnt out, it will get silently moved to a different sector and continue on it's merry way.

Hmm, I am talking out of my ass now, but I wonder if a larger drive that isn't full would have a longer lifetime than a smaller drive, simply because it has more places to replace dead sectors with.

Anyway, firefox slowing down probably doesn't have too much to do with a dying flash drive, simply because it does most everything in memory. Just be sure to crank up the in-memory cache and turn down the on-disk cache to nothing.
posted by cschneid at 9:50 AM on May 24, 2007

Flash memory spreads repeated writes out over the chips to avoid this exact problem. That is, since there's no seek time, there's no reason that a write to the FAT always has to end up in the same place in the memory. So that's what they do.
posted by kindall at 10:58 AM on May 24, 2007