> Most modern flash devices have cells that are writable at least 10
> times that - 100,000 cycles is the minimum you will find. Better
> devices have even higher cycle counts.
Glad to hear, but I would still prefer a hard-disk whose lifetime is
measured in "years", not in "cycles".
> DOM products have FLASH in them - Nobody said anything about DRAM.
> If they had DRAM they would have to be continuously powered.
Sad how a simple "battery" is not included in such devices, so maybe
low-power DRAM could be used for faster writes and longer lifetimes.
> Products like Disk on Module that are designed as hard drive
> replacements usually have better wear leveling capability than
> standard USB "thumb drives", as the directory meta data update issue
> is well known. SSDs take this to another level by "over provisioning"
> which means including more capacity than is advertised so that they
> will have enough spare capacity to make it to their rated lifetime.
I have never used any sort of "solid state" memory devices to replace
a hard disk, so the whole thought of "wear leveling" is a bit foreign
to me. With hard disks, one just "uses them", with no need or worry
about such techniques, for their 3- or 5-year lifetime. Maybe hard
disks could last better, using a cache or other "access minimization"
schemes -- But knowing how manufacturers make such disks last EXACTLY
their "warranty period", I really doubt it!
> For applications where fast access is required nothing can beat a
> FLASH based device. Part of the equation there involves unit life;
> if you use a FLASH based device in an environment with lots of writes
> then you expect to be replacing it on an accelerated schedule. The
> write and read throughput is far above what a conventional spinning
> disk can provide, although the capacities are far smaller.
Shall stay with hard disks, then. On my home "desktop" system, I am
NOT concerned about absolute speed (not with UIDE, anyway!) nor power
consumption, but I AM still "concerned" over all noted in this thread
re: FLASH-disk "cycle limits"! For me, and I expect a LOT of others
like me, a "garden variety" $40 hard disk should do just fine WITHOUT
any such "concerns"!
Jack R. Ellis
RSA(R) Conference 2012
Save $700 by Nov 18
Freedos-user mailing list