I also have an Epson flash card in my new HP. It's 10 meg. Again, no
problems with the card. The wear program that came with it was
defective and I was totaly unable to get any response from Epson. After
weeks of trying to call them at all hours with no success, and many many
requests for help or at least attention on thier Compuserve SIG, I finally
gave up and posted a message expressing my discontent and asking all users
to please notice that they've been unwilling to respond to my message, or
anyone else's, for several weeks.
The response I got from that was a private message from some nameless person
telling me to respond to this message with a fax number and that I would
receive further instructions on how to get help by fax within the next few
weeks. Needless to say, I didn't.
As you can probably tell, I'm still angry about this 6 months later. I did
find out from anonther user that the card was manufactured by Sundisk
and I was able to download a copy of the program from their sig.
The card has been without problems. It's also available under a number of
different names, including HP's name. It's manufactured by Sundisk.
Ace sells a newer technology flash card that uses less power and wears longer. They're also known for good customer support. The card is manufactured by
IBM but sold under the Ace naame. They also sell cards manufactured by
Sundisk.
An SRAM card is similar to the ram you use in your computer. It's Static
ram instead of Dynamic ram (SRAM vs DRAM). It's actually used for the
memory cache in computers because it's very fast compared to DRAM. It's
also very expensive. So it's not used as main memory. It also has the
advantage of using much less power than DRAM and that's why it's used
in PC cards. The SRAM cards come with a battery that keeps them from
forgetting things when you turn of the computer. Most of these batteries
last about a year, sometimes 2 but don't bet on it, and cost about 3.50
at Radio Shack. That's about all there is to know about SRAM.
Flash ram is a different animal alltogether. It's related to the CMOS in
your computer that holds the configuration information about your drives,
etc. It's not exactly the same thing but im told its a distant relative.
Flash ram is slow. Much slower than SRAM or even DRAM. But it's faster
than a hard drive and that's how it's used so it's no big deal.
It also requires a LOT of power to write to it. Reading it takes no more
power than SRAM but writing is a major power drain. I seem to get about
20-25% less battery life since I got my flash card. I'm not sure of that.
So if you're writing constantly to disk you probably don't want one.
It's also very slow writing. It's not nearly as slow reading.
The flash card has no internal backup battery. It doesn't need current
to keep it refreshed. This makes it very stable for important information.
In fact, the manufacturers say that it is the most permanent way we know
of to record data. That's probably good.
The big drawback of the flashcard is that they wear out. They estimate that
you can write to any given bit 100,000 times before it wears out. The
manufacturers translate that into a 10 year life for the average user. It
could also be a 2 week life for certain users. Or worse. That kept me
from getting one for a long time. But they come in much larger sizes and
meg per meg theyre a lot less expensive. So I got one.
The way it wears out is this. The more you write to an area, the slower it
is to respond and tell you it's written there. The write actually gets
slower and slower. It will eventually get so slow it will time out and
you'll get write errors. But the card is still fully readable at that
point.
The wear program helps that situation by writing all over the card and
seeing how long each write takes. It assumes that the slower areas are
getting more use and swaps data with some faster areas. This lets the
card wear evenly and extends the life. Kind of like rotating your tires.
Someone also told me that the cards have extra memory internally that
can be used to swap out with worn out parts. Then someone else said
that's not true. Both of these are people I trust and who should know.
Take that for what it's worth.
The wear program is said to extend the life of the flash card by from 3 to
10 times. But it only works on an HP palmtop or Omnibook computer. I
don't know why.
I've had mine for about 6 or 8 months. I've written to it a lot. So far,
every time I run the wear program it tells me it doesn't need wear leveling
yet. I guess that's a good sign.
That's about everything I know or have been told about SRAM and flash cards.
I hope it helps.
Barry