Re: Solid state HDD's for PC based controls

Hi Jon,

> Interesting. Wonder just how reliable they are.

Flash-type memories, as already alluded to, have a limited number of
write cycles (many have individual memory cells that can be
rewriteen 100K times). In practice more writes can occur because
there are often management facilities for "wear leveling" so that
the Least Recently Used memory is used to store the next data
written. This can dramatically extend the life of the memory if
there a lot of free memory.

The number of read cycles is essentially unlimited.

> Wouldn't a full on solid state
> drive also be flash memory?

I'm not sure what you mean by "full on solid state." There have
been available for years solid state drives that do not use Flash-
type memory, but static memory in conjunction with a battery
backup. These drives can be had in fair-sized configurations (I
think I may have seen 1 GB drive--which may be overkill for DOS but
may be tight for Windows), have the benefit of being able to be read
and written an unlimited number of times, but do require a reliable
battery for the memory to retain its contents when the power is off.

> Overall, I bet even in heavy use, I'd only be looking at a couple

write

> cycles a day. Still, perhaps I'd be better off getting one of the

disk

> bay units that can be set as slave, and simply use it for

backups...

You should be aware that some DOS apps can perform disk swapping to
overcome limits with physical memory--though I do not know if this
affects any currently-available DOS CAM apps.

Cheers,
Adrian