[mythtvnz] SSD Drives for video

[Mark]

> SLC is the older variety and MLC the newer variety, AFAICT.  Odd that
> newer varieties should be less durable.
> 
I haven't overly kept up to play with SSD changes in the past year but
did spend time investigating them for work a few years ago, we couldn't
get approval for the small RAMSAN device we would have liked (priced at
$50,000+) and there were many issues with all sorts of problems with
different brand SSDs and also problems with OS support, depending on
controllers used etc.  In the end I decided to get a couple of
reasonable SAMSUNG consumer drives on the basis that they should last a
couple of years before needing replacement and by then prices would have
dropped further (in practise not as quick as I thought they would) and
speed further improved (which they have).  The database usage was a
little unusual with mass amounts of random read/writes and mass amounts
of sequential IO (which stayed on hard drives) and being completely
unloaded and reloaded every few days.

SLC is much higher quality and MUCH more expensive, generally found in
enterprise drives.  MLC is a cheaper alternative where they use a
variety of techniques (wear levelling, extra non visible space etc) to
try and get an acceptable lifetime out of a drive.

Intensive small random writes used to be lifetime killers as writing one
byte required a full block write and cheaper drives didn't have overly
long write lifetime expectancies.

If you can afford them SSD's are fantastic.  For MythTv I now use one
for OS/database/development and all recordings are on hard disc drives.
My TV front end uses a SATA SSD DOM which isn't overly fast and may not
last long (I like my gear to last forever) as I haven't gotten around to
minimising logging but it's tiny, silent and was cheap on AliExpress.


Mark