Norman Dunbar wrote, on 4/Feb/11 15:46 | Feb4:
Ian,
How many erase/re-write cycles is each bit in modern flash memory good
for nowadays? SD cards would be great for storing libraries of programs
and data that don't change frequently, but what about using them, for
example, for frequently changing temporary files generated by running
programs (the sort of thing we should probably use RAMdisks for given
enough RAM)? Do hard-disks still have the advantage there?
A lot of them nowadays have "load balancing" code in the hardware. If it
notices a hot spot, it reorganises the data to avoid that hot spot.
Cheaper ones, probably done.
I agree. Romdisq is 100,000 writes, but it too has load balancing.
I have had very very few back with failed chips. The key is not filling
it with data.
I wonder as well if the hardware is clever enough to *not* write out
unchanged bits. That would save a *lot* of wear.
I have a 256 Mb From Crucial which I wrote about many years ago in QL
Toady - around 2002 or 2003, it still works and is in use daily. I
continually read and rewrite it.
It is my own "QL On a Stick with QPC" and two hard drives, plus it
contans my subversion repositories for my QL Toady articles, my work on
Firebird Database Docs, programming projects and so on. It also gets
quite well hammered as a general purpose "floppy disc" as I copy stuff
from my laptop to my desktop using it, and delete the files afterwards.
Deletion of course is only the directory entry.
So, buy your cards from a reputable source, pay a little extra for them,
and you should be fine. I recommend http://www.crucial.com/uk - service
is excellent and quaility is likewise, excellent.
.. and of course price is high (8-)#
worldnews.com uses a 1Tb SSD raid 5 (based on flash of course) for its
index store, and works very well. It is very low power and hugely fast
reading. This mighty server with 40GB ram and 12 processors uses only
1.5 amps. Mind you it cost £23,000!
Tony
--
QBBS (QL fido BBS 2:257/67) +44(0)1442-828255
t...@firshman.co.uk http://firshman.co.uk
Voice: +44(0)1442-828254 Fax: +44(0)1442-828255 Skype: tonyfirshman
TF Services, 29 Longfield Road, TRING, Herts, HP23 4DG
_______________________________________________
QL-Users Mailing List
http://www.q-v-d.demon.co.uk/smsqe.htm
